iOS 开发常用的代码块

2017-08-12 20:15:35来源:CSDN作者:bobbob32人点击

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1、设置UILabel行间距

NSMutableAttributedString* attrString = [[NSMutableAttributedString  alloc] initWithString:label.text];    NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];    [style setLineSpacing:20];    [attrString addAttribute:NSParagraphStyleAttributeName value:style range:NSMakeRange(0, label.text.length)];    label.attributedText = attrString;

// 或者使用xib,看下gif图

这里写图片描述

Untitled.gif

2、当使用-performSelector:withObject:withObject:afterDelay:方法时,需要传入多参数问题

// 方法一、// 把参数放进一个数组/字典,直接把数组/字典当成一个参数传过去,具体方法实现的地方再解析这个数组/字典NSArray * array =     [NSArray arrayWithObjects: @"first", @"second", nil];[self performSelector:@selector(fooFirstInput:) withObject: array afterDelay:15.0];// 方法二、// 使用NSInvocationSEL aSelector = NSSelectorFromString(@"doSoming:argument2:");    NSInteger argument1 = 10;    NSString *argument2 = @"argument2";    if([self respondsToSelector:aSelector]) {        NSInvocation *inv = [NSInvocation invocationWithMethodSignature:[self methodSignatureForSelector:aSelector]];        [inv setSelector:aSelector];        [inv setTarget:self];        [inv setArgument:&(argument1) atIndex:2];        [inv setArgument:&(argument2) atIndex:3];        [inv performSelector:@selector(invoke) withObject:nil afterDelay:15.0];    }

3、UILabel显示不同颜色字体

NSMutableAttributedString * string = [[NSMutableAttributedString alloc] initWithString:label.text];[string addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0,5)];[string addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(5,6)];[string addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(11,5)];label.attributedText = string;

4、比较两个CGRect/CGSize/CGPoint是否相等

if (CGRectEqualToRect(rect1, rect2)) { // 两个区域相等        // do some    }    if (CGPointEqualToPoint(point1, point2)) { // 两个点相等        // do some    }    if (CGSizeEqualToSize(size1, size2)) { // 两个size相等        // do some    }

5、比较两个NSDate相差多少小时

 NSDate* date1 = someDate; NSDate* date2 = someOtherDate; NSTimeInterval distanceBetweenDates = [date1 timeIntervalSinceDate:date2]; double secondsInAnHour = 3600;// 除以3600是把秒化成小时,除以60得到结果为相差的分钟数 NSInteger hoursBetweenDates = distanceBetweenDates / secondsInAnHour;

6、每个cell之间增加间距

// 方法一,每个分区只显示一行cell,分区头当作你想要的间距(注意,从数据源数组中取值的时候需要用indexPath.section而不是indexPath.row)- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{    return yourArry.count;}- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{    return 1;}-(CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section{    return cellSpacingHeight;}// 方法二,在cell的contentView上加个稍微低一点的view,cell上原本的内容放在你的view上,而不是contentView上,这样能伪造出一个间距来。// 方法三,自定义cell,重写setFrame:方法- (void)setFrame:(CGRect)frame{    frame.size.height -= 20;    [super setFrame:frame];}

7、播放一张张连续的图片

// 加入现在有三张图片分别为animate_1、animate_2、animate_3// 方法一    imageView.animationImages = @[[UIImage imageNamed:@"animate_1"], [UIImage imageNamed:@"animate_2"], [UIImage imageNamed:@"animate_3"]];imageView.animationDuration = 1.0;// 方法二    imageView.image = [UIImage animatedImageNamed:@"animate_" duration:1.0];// 方法二解释下,这个方法会加载animate_为前缀的,后边0-1024,也就是animate_0、animate_1一直到animate_1024

8、加载gif图片

推荐使用这个框架 FLAnimatedImage

9、防止离屏渲染为image添加圆角

// image分类- (UIImage *)circleImage{// NO代表透明UIGraphicsBeginImageContextWithOptions(self.size, NO, 1);// 获得上下文CGContextRef ctx = UIGraphicsGetCurrentContext();// 添加一个圆CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);// 方形变圆形CGContextAddEllipseInRect(ctx, rect);// 裁剪CGContextClip(ctx);// 将图片画上去[self drawInRect:rect];UIImage *image = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();return image;}

10、查看系统所有字体

// 打印字体for (id familyName in [UIFont familyNames]) {    NSLog(@"%@", familyName);    for (id fontName in [UIFont fontNamesForFamilyName:familyName]) NSLog(@"  %@", fontName);}// 也可以进入这个网址查看 http://iosfonts.com/

11、获取随机数

NSInteger i = arc4random();

12、获取随机数小数(0-1之间)

#define ARC4RANDOM_MAX       double val = ((double)arc4random() / ARC4RANDOM_MAX);

13、AVPlayer视频播放完成的通知监听

[[NSNotificationCenter defaultCenter]       addObserver:self      selector:@selector(videoPlayEnd)      name:AVPlayerItemDidPlayToEndTimeNotification       object:nil];

14、判断两个rect是否有交叉

 if (CGRectIntersectsRect(rect1, rect2)) {}

15、判断一个字符串是否为数字

NSCharacterSet *notDigits = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];    if ([str rangeOfCharacterFromSet:notDigits].location == NSNotFound)    {      // 是数字    } else    {      // 不是数字    }

16、将一个view保存为pdf格式

- (void)createPDFfromUIView:(UIView*)aView saveToDocumentsWithFileName:(NSString*)aFilename{    NSMutableData *pdfData = [NSMutableData data];    UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil);    UIGraphicsBeginPDFPage();    CGContextRef pdfContext = UIGraphicsGetCurrentContext();    [aView.layer renderInContext:pdfContext];    UIGraphicsEndPDFContext();    NSArray* documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);    NSString* documentDirectory = [documentDirectories objectAtIndex:0];    NSString* documentDirectoryFilename = [documentDirectory stringByAppendingPathComponent:aFilename];    [pdfData writeToFile:documentDirectoryFilename atomically:YES];    NSLog(@"documentDirectoryFileName: %@",documentDirectoryFilename);}

17、让一个view在父视图中心

child.center = [parent convertPoint:parent.center fromView:parent.superview];

18、获取当前导航控制器下前一个控制器

- (UIViewController *)backViewController{    NSInteger myIndex = [self.navigationController.viewControllers indexOfObject:self];    if ( myIndex != 0 && myIndex != NSNotFound ) {        return [self.navigationController.viewControllers objectAtIndex:myIndex-1];    } else {        return nil;    }}

19、保存UIImage到本地

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);NSString *filePath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"Image.png"];[UIImagePNGRepresentation(image) writeToFile:filePath atomically:YES];

20、键盘上方增加工具栏

UIToolbar *keyboardDoneButtonView = [[UIToolbar alloc] init];[keyboardDoneButtonView sizeToFit];UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithTitle:@"Done"                                                               style:UIBarButtonItemStyleBordered target:self                                                              action:@selector(doneClicked:)];[keyboardDoneButtonView setItems:[NSArray arrayWithObjects:doneButton, nil]];txtField.inputAccessoryView = keyboardDoneButtonView;

21、copy一个view

因为UIView没有实现copy协议,因此找不到copyWithZone方法,使用copy的时候导致崩溃

但是我们可以通过归档再解档实现copy,这相当于对视图进行了一次深拷贝,代码如下

id copyOfView = [NSKeyedUnarchiver unarchiveObjectWithData:[NSKeyedArchiver archivedDataWithRootObject:originalView]];

22、在image上绘制文字并生成新的image

UIFont *font = [UIFont boldSystemFontOfSize:12];    UIGraphicsBeginImageContext(image.size);    [image drawInRect:CGRectMake(0,0,image.size.width,image.size.height)];    CGRect rect = CGRectMake(point.x, point.y, image.size.width, image.size.height);    [[UIColor whiteColor] set];    [text drawInRect:CGRectIntegral(rect) withFont:font];     UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();

23、判断一个view是否为另一个view的子视图

// 如果myView是self.view本身,也会返回yesBOOL isSubView = [myView isDescendantOfView:self.view];

24、判断一个字符串是否包含另一个字符串

// 方法一、这种方法只适用于iOS8之后,如果是配iOS8之前用方法二if ([str containsString:otherStr]) NSLog(@"包含");// 方法二NSRange range = [str rangeOfString:otherStr];if (range.location != NSNotFound) NSLog(@"包含");

25、UICollectionView自动滚动到某行

// 重写viewDidLayoutSubviews方法-(void)viewDidLayoutSubviews {   [super viewDidLayoutSubviews];   [self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionCenteredVertically animated:NO];}

26、修改系统UIAlertController

// 但是据说这种方法会被App Store拒绝(慎用!)UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:@"" message:@"" preferredStyle:UIAlertControllerStyleActionSheet];    NSMutableAttributedString *hogan = [[NSMutableAttributedString alloc] initWithString:@"我是一个大文本"];    [hogan addAttribute:NSFontAttributeName                  value:[UIFont systemFontOfSize:30]                  range:NSMakeRange(4, 1)];    [hogan addAttribute:NSForegroundColorAttributeName                  value:[UIColor redColor]                  range:NSMakeRange(4, 1)];    [alertVC setValue:hogan forKey:@"attributedTitle"];    UIAlertAction *button = [UIAlertAction actionWithTitle:@"Label text" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action){ }];    UIImage *accessoryImage = [UIImage imageNamed:@"1"];    [button setValue:accessoryImage forKey:@"image"];    [alertVC addAction:button];    [self presentViewController:alertVC animated:YES completion:nil];

27、判断某一行的cell是否已经显示

CGRect cellRect = [tableView rectForRowAtIndexPath:indexPath];BOOL completelyVisible = CGRectContainsRect(tableView.bounds, cellRect);

28、让导航控制器pop回指定的控制器

NSMutableArray *allViewControllers = [NSMutableArray arrayWithArray:[self.navigationController viewControllers]];for (UIViewController *aViewController in allViewControllers) {    if ([aViewController isKindOfClass:[RequiredViewController class]]) {        [self.navigationController popToViewController:aViewController animated:NO];    }}

29、动画修改label上的文字

// 方法一CATransition *animation = [CATransition animation];    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];    animation.type = kCATransitionFade;    animation.duration = 0.75;    [self.label.layer addAnimation:animation forKey:@"kCATransitionFade"];    self.label.text = @"New";// 方法二[UIView transitionWithView:self.label                      duration:0.25f                       options:UIViewAnimationOptionTransitionCrossDissolve                    animations:^{                        self.label.text = @"Well done!";                    } completion:nil];// 方法三[UIView animateWithDuration:1.0                     animations:^{                         self.label.alpha = 0.0f;                         self.label.text = @"newText";                         self.label.alpha = 1.0f;                     }];

30、判断字典中是否包含某个key值

if ([dic objectForKey:@"yourKey"]) {    NSLog(@"有这个值");} else {    NSLog(@"没有这个值");}

31、获取屏幕方向

UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;if(orientation == 0) //Default orientation     //默认else if(orientation == UIInterfaceOrientationPortrait)    //竖屏else if(orientation == UIInterfaceOrientationLandscapeLeft)    // 左横屏else if(orientation == UIInterfaceOrientationLandscapeRight)    //右横屏

32、设置UIImage的透明度

// 方法一、添加UIImage分类- (UIImage *)imageByApplyingAlpha:(CGFloat) alpha {    UIGraphicsBeginImageContextWithOptions(self.size, NO, 0.0f);    CGContextRef ctx = UIGraphicsGetCurrentContext();    CGRect area = CGRectMake(0, 0, self.size.width, self.size.height);    CGContextScaleCTM(ctx, 1, -1);    CGContextTranslateCTM(ctx, 0, -area.size.height);    CGContextSetBlendMode(ctx, kCGBlendModeMultiply);    CGContextSetAlpha(ctx, alpha);    CGContextDrawImage(ctx, area, self.CGImage);    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    return newImage;}// 方法二、如果没有奇葩需求,干脆用UIImageView设置透明度UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageWithName:@"yourImage"]];imageView.alpha = 0.5;

33、Attempt to mutate immutable object with insertString:atIndex:

这个错是因为你拿字符串调用insertString:atIndex:方法的时候,调用对象不是NSMutableString,应该先转成这个类型再调用

34、UIWebView添加单击手势不响应

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(webViewClick)];        tap.delegate = self;        [_webView addGestureRecognizer:tap];// 因为webView本身有一个单击手势,所以再添加会造成手势冲突,从而不响应。需要绑定手势代理,并实现下边的代理方法- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{    return YES;}

35、获取手机RAM容量

// 需要导入#importmach_port_t host_port;    mach_msg_type_number_t host_size;    vm_size_t pagesize;    host_port = mach_host_self();    host_size = sizeof(vm_statistics_data_t) / sizeof(integer_t);    host_page_size(host_port, &pagesize);    vm_statistics_data_t vm_stat;    if (host_statistics(host_port, HOST_VM_INFO, (host_info_t)&vm_stat, &host_size) != KERN_SUCCESS) {        NSLog(@"Failed to fetch vm statistics");    }    /* Stats in bytes */    natural_t mem_used = (vm_stat.active_count +                          vm_stat.inactive_count +                          vm_stat.wire_count) * pagesize;    natural_t mem_free = vm_stat.free_count * pagesize;    natural_t mem_total = mem_used + mem_free;    NSLog(@"已用: %u 可用: %u 总共: %u", mem_used, mem_free, mem_total);

36、地图上两个点之间的实际距离

// 需要导入#importCLLocation *locA = [[CLLocation alloc] initWithLatitude:34 longitude:113];    CLLocation *locB = [[CLLocation alloc] initWithLatitude:31.05 longitude:121.76];// CLLocationDistance求出的单位为米    CLLocationDistance distance = [locA distanceFromLocation:locB];

37、在应用中打开设置的某个界面

// 打开设置->通用[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=General"]];// 以下是设置其他界面prefs:root=General&path=Aboutprefs:root=General&path=ACCESSIBILITYprefs:root=AIRPLANE_MODEprefs:root=General&path=AUTOLOCKprefs:root=General&path=USAGE/CELLULAR_USAGEprefs:root=Brightnessprefs:root=Bluetoothprefs:root=General&path=DATE_AND_TIMEprefs:root=FACETIMEprefs:root=Generalprefs:root=General&path=Keyboardprefs:root=CASTLEprefs:root=CASTLE&path=STORAGE_AND_BACKUPprefs:root=General&path=INTERNATIONALprefs:root=LOCATION_SERVICESprefs:root=ACCOUNT_SETTINGSprefs:root=MUSICprefs:root=MUSIC&path=EQprefs:root=MUSIC&path=VolumeLimitprefs:root=General&path=Networkprefs:root=NIKE_PLUS_IPODprefs:root=NOTESprefs:root=NOTIFICATIONS_IDprefs:root=Phoneprefs:root=Photosprefs:root=General&path=ManagedConfigurationListprefs:root=General&path=Resetprefs:root=Sounds&path=Ringtoneprefs:root=Safariprefs:root=General&path=Assistantprefs:root=Soundsprefs:root=General&path=SOFTWARE_UPDATE_LINKprefs:root=STOREprefs:root=TWITTERprefs:root=FACEBOOKprefs:root=General&path=USAGE prefs:root=VIDEOprefs:root=General&path=Network/VPNprefs:root=Wallpaperprefs:root=WIFIprefs:root=INTERNET_TETHERINGprefs:root=Phone&path=Blockedprefs:root=DO_NOT_DISTURB

38、在UITextView中显示html文本

  UITextView *textView = [[UITextView alloc] initWithFrame:CGRectMake(20, 30, 100, 199)];    textView.backgroundColor = [UIColor redColor];    [self.view addSubview:textView];    NSString *htmlString = @"![](http://blogs.babble.com/famecrawler/files/2010/11/mickey_mouse-1097.jpg)";    NSAttributedString *attributedString = [[NSAttributedString alloc] initWithData: [htmlString dataUsingEncoding:NSUnicodeStringEncoding] options: @{ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType } documentAttributes: nil error: nil];    textView.attributedText = attributedString;

39、监听scrollView是否滚动到了顶部/底部

-(void)scrollViewDidScroll: (UIScrollView*)scrollView{    float scrollViewHeight = scrollView.frame.size.height;    float scrollContentSizeHeight = scrollView.contentSize.height;    float scrollOffset = scrollView.contentOffset.y;    if (scrollOffset == 0)    {        // 滚动到了顶部    }    else if (scrollOffset + scrollViewHeight == scrollContentSizeHeight)    {        // 滚动到了底部    }}

40、UISlider增量/减量为固定值(假如为5)

- (void)setupSlider{    UISlider *slider = [[UISlider alloc] init];    [self.view addSubview:slider];    [slider addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventValueChanged];    slider.maximumValue = 100;    slider.minimumValue = 0;    slider.frame = CGRectMake(200, 20, 100, 30);}- (void)sliderAction:(UISlider *)slider{    [slider setValue:((int)((slider.value + 2.5) / 5) * 5) animated:NO];}

41、选中textField或者textView所有文本(我这里以textView为例)

[self.textView setSelectedTextRange:[self.textView textRangeFromPosition:self.textView.beginningOfDocument toPosition:self.textView.endOfDocument]]

42、从导航控制器中删除某个控制器

// 方法一、知道这个控制器所处的导航控制器下标NSMutableArray *navigationArray = [[NSMutableArray alloc] initWithArray: self.navigationController.viewControllers];[navigationArray removeObjectAtIndex: 2]; self.navigationController.viewControllers = navigationArray;// 方法二、知道具体是哪个控制器NSArray* tempVCA = [self.navigationController viewControllers];for(UIViewController *tempVC in tempVCA){    if([tempVC isKindOfClass:[urViewControllerClass class]])    {        [tempVC removeFromParentViewController];    }}

43、隐藏UITextView/UITextField光标

textField.tintColor = [UIColor clearColor];

44、当UITextView/UITextField中没有文字时,禁用回车键

textField.enablesReturnKeyAutomatically = YES;

45、字符串encode编码(编码url字符串不成功的问题)

// 我们一般用这个方法处理stringByAddingPercentEscapesUsingEncoding但是这个方法好想不会处理/和&这种特殊符号,这种情况就需要用下边这个方法处理@implementation NSString (NSString_Extended)- (NSString *)urlencode {    NSMutableString *output = [NSMutableString string];    const unsigned char *source = (const unsigned char *)[self UTF8String];    int sourceLen = strlen((const char *)source);    for (int i = 0; i < sourceLen; ++i) {        const unsigned char thisChar = source[i];        if (thisChar == ' '){            [output appendString:@"+"];        } else if (thisChar == '.' || thisChar == '-' || thisChar == '_' || thisChar == '~' ||                    (thisChar >= 'a' && thisChar = 'A' && thisChar = '0' && thisChar <= '9')) {            [output appendFormat:@"%c", thisChar];        } else {            [output appendFormat:@"%%X", thisChar];        }    }    return output;}

46、计算UILabel上某段文字的frame

@implementation UILabel (TextRect)- (CGRect)boundingRectForCharacterRange:(NSRange)range{    NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:[self attributedText]];    NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];    [textStorage addLayoutManager:layoutManager];    NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:[self bounds].size];    textContainer.lineFragmentPadding = 0;    [layoutManager addTextContainer:textContainer];    NSRange glyphRange;    [layoutManager characterRangeForGlyphRange:range actualGlyphRange:&glyphRange];    return [layoutManager boundingRectForGlyphRange:glyphRange inTextContainer:textContainer];}

47、获取随机UUID

NSString *result;    if([[[UIDevice currentDevice] systemVersion] floatValue] > 6.0)    {       result = [[NSUUID UUID] UUIDString];    }    else    {        CFUUIDRef uuidRef = CFUUIDCreate(NULL);        CFStringRef uuid = CFUUIDCreateString(NULL, uuidRef);        CFRelease(uuidRef);        result = (__bridge_transfer NSString *)uuid;    }

48、仿苹果抖动动画

#define RADIANS(degrees) (((degrees) * M_PI) / 180.0)- (void)startAnimate {    view.transform = CGAffineTransformRotate(CGAffineTransformIdentity, RADIANS(-5));    [UIView animateWithDuration:0.25 delay:0.0 options:(UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse) animations:^ {                         view.transform = CGAffineTransformRotate(CGAffineTransformIdentity, RADIANS(5));                     } completion:nil];}- (void)stopAnimate {    [UIView animateWithDuration:0.25 delay:0.0 options:(UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionCurveLinear) animations:^ {                         view.transform = CGAffineTransformIdentity;                     } completion:nil];}

49、修改UISearBar内部背景颜色

UITextField *textField = [_searchBar valueForKey:@"_searchField"];textField.backgroundColor = [UIColor redColor];

50、UITextView滚动到顶部

    // 方法一    [self.textView scrollRangeToVisible:NSMakeRange(0, 0)];    // 方法二    [self.textView setContentOffset:CGPointZero animated:YES];

51、通知监听APP生命周期

UIApplicationDidEnterBackgroundNotification 应用程序进入后台UIApplicationWillEnterForegroundNotification 应用程序将要进入前台UIApplicationDidFinishLaunchingNotification 应用程序完成启动UIApplicationDidFinishLaunchingNotification 应用程序由挂起变的活跃UIApplicationWillResignActiveNotification 应用程序挂起(有电话进来或者锁屏)UIApplicationDidReceiveMemoryWarningNotification 应用程序收到内存警告UIApplicationDidReceiveMemoryWarningNotification 应用程序终止(后台杀死、手机关机等)UIApplicationSignificantTimeChangeNotification 当有重大时间改变(凌晨0点,设备时间被修改,时区改变等)UIApplicationWillChangeStatusBarOrientationNotification 设备方向将要改变UIApplicationDidChangeStatusBarOrientationNotification 设备方向改变UIApplicationWillChangeStatusBarFrameNotification 设备状态栏frame将要改变UIApplicationDidChangeStatusBarFrameNotification 设备状态栏frame改变UIApplicationBackgroundRefreshStatusDidChangeNotification 应用程序在后台下载内容的状态发生变化UIApplicationProtectedDataWillBecomeUnavailable 本地受保护的文件被锁定,无法访问UIApplicationProtectedDataWillBecomeUnavailable 本地受保护的文件可用了

52、触摸事件类型

UIControlEventTouchCancel 取消控件当前触发的事件
UIControlEventTouchDown 点按下去的事件
UIControlEventTouchDownRepeat 重复的触动事件
UIControlEventTouchDragEnter 手指被拖动到控件的边界的事件
UIControlEventTouchDragExit 一个手指从控件内拖到外界的事件
UIControlEventTouchDragInside 手指在控件的边界内拖动的事件
UIControlEventTouchDragOutside 手指在控件边界之外被拖动的事件
UIControlEventTouchUpInside 手指处于控制范围内的触摸事件
UIControlEventTouchUpOutside 手指超出控制范围的控制中的触摸事件
53、UITextField文字周围增加边距

    // 子类化UITextField,增加insert属性@interface WZBTextField : UITextField@property (nonatomic, assign) UIEdgeInsets insets;@end// 在.m文件重写下列方法- (CGRect)textRectForBounds:(CGRect)bounds {    CGRect paddedRect = UIEdgeInsetsInsetRect(bounds, self.insets);    if (self.rightViewMode == UITextFieldViewModeAlways || self.rightViewMode == UITextFieldViewModeUnlessEditing) {        return [self adjustRectWithWidthRightView:paddedRect];    }    return paddedRect;}- (CGRect)placeholderRectForBounds:(CGRect)bounds {    CGRect paddedRect = UIEdgeInsetsInsetRect(bounds, self.insets);    if (self.rightViewMode == UITextFieldViewModeAlways || self.rightViewMode == UITextFieldViewModeUnlessEditing) {        return [self adjustRectWithWidthRightView:paddedRect];    }    return paddedRect;}- (CGRect)editingRectForBounds:(CGRect)bounds {    CGRect paddedRect = UIEdgeInsetsInsetRect(bounds, self.insets);    if (self.rightViewMode == UITextFieldViewModeAlways || self.rightViewMode == UITextFieldViewModeWhileEditing) {        return [self adjustRectWithWidthRightView:paddedRect];    }    return paddedRect;}- (CGRect)adjustRectWithWidthRightView:(CGRect)bounds {    CGRect paddedRect = bounds;    paddedRect.size.width -= CGRectGetWidth(self.rightView.frame);    return paddedRect;}

54、监听UISlider拖动状态

// 添加事件[slider addTarget:self action:@selector(sliderValurChanged:forEvent:) forControlEvents:UIControlEventValueChanged];// 实现方法- (void)sliderValurChanged:(UISlider*)slider forEvent:(UIEvent*)event {    UITouch *touchEvent = [[event allTouches] anyObject];    switch (touchEvent.phase) {        case UITouchPhaseBegan:            NSLog(@"开始拖动");            break;        case UITouchPhaseMoved:            NSLog(@"正在拖动");            break;        case UITouchPhaseEnded:            NSLog(@"结束拖动");            break;        default:            break;    }}

55、设置UITextField光标位置

// textField需要设置的textField,index要设置的光标位置- (void)cursorLocation:(UITextField *)textField index:(NSInteger)index{    NSRange range = NSMakeRange(index, 0);    UITextPosition *start = [textField positionFromPosition:[textField beginningOfDocument] offset:range.location];    UITextPosition *end = [textField positionFromPosition:start offset:range.length];    [textField setSelectedTextRange:[textField textRangeFromPosition:start toPosition:end]];}

56、去除webView底部黑色

    [webView setBackgroundColor:[UIColor clearColor]];    [webView setOpaque:NO];    for (UIView *v1 in [webView subviews])    {        if ([v1 isKindOfClass:[UIScrollView class]])        {            for (UIView *v2 in v1.subviews)            {                if ([v2 isKindOfClass:[UIImageView class]])                {                    v2.hidden = YES;                }            }        }    }

57、获取collectionViewCell在屏幕中的frame

UICollectionViewLayoutAttributes *attributes = [collectionView layoutAttributesForItemAtIndexPath:indexPath];CGRect cellRect = attributes.frame;CGRect cellFrameInSuperview = [collectionView convertRect:cellRect toView:[cv superview]];

58、比较两个UIImage是否相等

- (BOOL)image:(UIImage *)image1 isEqualTo:(UIImage *)image2{    NSData *data1 = UIImagePNGRepresentation(image1);    NSData *data2 = UIImagePNGRepresentation(image2);    return [data1 isEqual:data2];}

59、解决当UIScrollView上有UIButton的时候,触摸到button滑动不了的问题

// 子类化UIScrollView,并重写以下方法- (instancetype)initWithFrame:(CGRect)frame {    if (self = [super initWithFrame:frame]) {        self.delaysContentTouches = NO;    }    return self;}- (BOOL)touchesShouldCancelInContentView:(UIView *)view {    if ([view isKindOfClass:UIButton.class]) {        return YES;    }    return [super touchesShouldCancelInContentView:view];}

60、UITextView中的文字添加阴影效果

- (void)setTextLayer:(UITextView *)textView color:(UIColor *)color{    CALayer *textLayer = ((CALayer *)[textView.layer.sublayers objectAtIndex:0]);    textLayer.shadowColor = color.CGColor;    textLayer.shadowOffset = CGSizeMake(0.0f, 1.0f);    textLayer.shadowOpacity = 1.0f;    textLayer.shadowRadius = 1.0f;}

61、MD5加密

+ (NSString *)md5:(NSString *)str{    const char *concat_str = [str UTF8String];    unsigned char result[CC_MD5_DIGEST_LENGTH];    CC_MD5(concat_str, (unsigned int)strlen(concat_str), result);    NSMutableString *hash = [NSMutableString string];    for (int i =0; i<16; i++){        [hash appendFormat:@"X", result[i]];    }    return [hash uppercaseString];}

62、base64加密

@interface NSData (Base64)/** *  @brief  字符串base64后转data */+ (NSData *)dataWithBase64EncodedString:(NSString *)string{    if (![string length]) return nil;    NSData *decoded = nil;#if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_9 || __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_7_0    if (![NSData instancesRespondToSelector:@selector(initWithBase64EncodedString:options:)])    {#pragma clang diagnostic push#pragma clang diagnostic ignored "-Wdeprecated-declarations"        decoded = [[self alloc] initWithBase64Encoding:[string stringByReplacingOccurrencesOfString:@"[^A-Za-z0-9+/=]" withString:@"" options:NSRegularExpressionSearch range:NSMakeRange(0, [string length])]];#pragma clang diagnostic pop    }    else#endif    {        decoded = [[self alloc] initWithBase64EncodedString:string options:NSDataBase64DecodingIgnoreUnknownCharacters];    }    return [decoded length]? decoded: nil;}/** *  @brief  NSData转string *  @param wrapWidth 换行长度  76  64 */- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth{    if (![self length]) return nil;    NSString *encoded = nil;#if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_9 || __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_7_0    if (![NSData instancesRespondToSelector:@selector(base64EncodedStringWithOptions:)])    {#pragma clang diagnostic push#pragma clang diagnostic ignored "-Wdeprecated-declarations"        encoded = [self base64Encoding];#pragma clang diagnostic pop    }    else#endif    {        switch (wrapWidth)        {            case 64:            {                return [self base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];            }            case 76:            {                return [self base64EncodedStringWithOptions:NSDataBase64Encoding76CharacterLineLength];            }            default:            {                encoded = [self base64EncodedStringWithOptions:(NSDataBase64EncodingOptions)0];            }        }    }    if (!wrapWidth || wrapWidth >= [encoded length])    {        return encoded;    }    wrapWidth = (wrapWidth / 4) * 4;    NSMutableString *result = [NSMutableString string];    for (NSUInteger i = 0; i < [encoded length]; i+= wrapWidth)    {        if (i + wrapWidth >= [encoded length])        {            [result appendString:[encoded substringFromIndex:i]];            break;        }        [result appendString:[encoded substringWithRange:NSMakeRange(i, wrapWidth)]];        [result appendString:@"/r/n"];    }    return result;}/** *  @brief  NSData转string 换行长度默认64 */- (NSString *)base64EncodedString{    return [self base64EncodedStringWithWrapWidth:0];}

63、AES加密

#import@interface NSData (AES)/** *  利用AES加密数据 */- (NSData*)encryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv {    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];    size_t dataMoved;    NSMutableData *encryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSizeAES128];    CCCryptorStatus status = CCCrypt(kCCEncrypt,kCCAlgorithmAES128,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,encryptedData.mutableBytes, encryptedData.length,&dataMoved);    if (status == kCCSuccess) {        encryptedData.length = dataMoved;        return encryptedData;    }    return nil;}/** *  @brief  利用AES解密据 */- (NSData*)decryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv {    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];    size_t dataMoved;    NSMutableData *decryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSizeAES128];    CCCryptorStatus result = CCCrypt(kCCDecrypt,kCCAlgorithmAES128,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,decryptedData.mutableBytes, decryptedData.length,&dataMoved);    if (result == kCCSuccess) {        decryptedData.length = dataMoved;        return decryptedData;    }    return nil;}

64、3DES加密

#import@interface NSData (3DES)/** *  利用3DES加密数据 */- (NSData*)encryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv {    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];    size_t dataMoved;    NSMutableData *encryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSize3DES];    CCCryptorStatus result = CCCrypt(kCCEncrypt,kCCAlgorithm3DES,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,encryptedData.mutableBytes,encryptedData.length,&dataMoved);    if (result == kCCSuccess) {        encryptedData.length = dataMoved;        return encryptedData;    }    return nil;}/** *  @brief   利用3DES解密数据 */- (NSData*)decryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv {    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];    size_t dataMoved;    NSMutableData *decryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSize3DES];    CCCryptorStatus result = CCCrypt(kCCDecrypt,kCCAlgorithm3DES,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,decryptedData.mutableBytes,decryptedData.length,&dataMoved);    if (result == kCCSuccess) {        decryptedData.length = dataMoved;        return decryptedData;    }    return nil;}

65、单个页面多个网络请求的情况,需要监听所有网络请求结束后刷新UI

dispatch_group_t group = dispatch_group_create();    dispatch_queue_t serialQueue = dispatch_queue_create("com.wzb.test.www", DISPATCH_QUEUE_SERIAL);    dispatch_group_enter(group);    dispatch_group_async(group, serialQueue, ^{        // 网络请求一        [WebClick getDataSuccess:^(ResponseModel *model) {            dispatch_group_leave(group);        } failure:^(NSString *err) {            dispatch_group_leave(group);        }];    });    dispatch_group_enter(group);    dispatch_group_async(group, serialQueue, ^{        // 网络请求二        [WebClick getDataSuccess:getBigTypeRM onSuccess:^(ResponseModel *model) {            dispatch_group_leave(group);        }                                  failure:^(NSString *errorString) {            dispatch_group_leave(group);        }];    });    dispatch_group_enter(group);    dispatch_group_async(group, serialQueue, ^{        // 网络请求三        [WebClick getDataSuccess:^{            dispatch_group_leave(group);        } failure:^(NSString *errorString) {            dispatch_group_leave(group);        }];    });    // 所有网络请求结束后会来到这个方法    dispatch_group_notify(group, serialQueue, ^{        dispatch_async(dispatch_get_global_queue(0, 0), ^{            dispatch_async(dispatch_get_main_queue(), ^{                // 刷新UI            });        });    });

66、解决openUrl延时问题

// 方法一dispatch_async(dispatch_get_main_queue(), ^{    UIApplication *application = [UIApplication sharedApplication];    if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) {        [application openURL:URL options:@{}           completionHandler:nil];    } else {        [application openURL:URL];    }    });// 方法二[self performSelector:@selector(redirectToURL:) withObject:url afterDelay:0.1];- (void) redirectToURL{UIApplication *application = [UIApplication sharedApplication];    if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) {        [application openURL:URL options:@{}           completionHandler:nil];    } else {        [application openURL:URL];    }}

67、页面跳转实现翻转动画

// modal方式    TestViewController *vc = [[TestViewController alloc] init];    vc.view.backgroundColor = [UIColor redColor];    vc.modalTransitionStyle = UIModalTransitionStyleCoverVertical;    [self presentViewController:vc animated:YES completion:nil];// push方式    TestViewController *vc = [[TestViewController alloc] init];    vc.view.backgroundColor = [UIColor redColor];    [UIView beginAnimations:@"View Flip" context:nil];    [UIView setAnimationDuration:0.80];    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.navigationController.view cache:NO];    [self.navigationController pushViewController:vc animated:YES];    [UIView commitAnimations];

68、tableView实现无限滚动

- (void)scrollViewDidScroll:(UIScrollView *)scrollView{    CGFloat actualPosition = scrollView.contentOffset.y;    CGFloat contentHeight = scrollView.contentSize.height - scrollView.frame.size.height;    if (actualPosition >= contentHeight) {        [self.dataArr addObjectsFromArray:self.dataArr];        [self.tableView reloadData];    }}

69、代码方式调整屏幕亮度

// brightness属性值在0-1之间,0代表最小亮度,1代表最大亮度[[UIScreen mainScreen] setBrightness:0.5];

70、获取当前应用CUP用量

float cpu_usage(){    kern_return_t kr;    task_info_data_t tinfo;    mach_msg_type_number_t task_info_count;    task_info_count = TASK_INFO_MAX;    kr = task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)tinfo, &task_info_count);    if (kr != KERN_SUCCESS) {        return -1;    }    task_basic_info_t      basic_info;    thread_array_t         thread_list;    mach_msg_type_number_t thread_count;    thread_info_data_t     thinfo;    mach_msg_type_number_t thread_info_count;    thread_basic_info_t basic_info_th;    uint32_t stat_thread = 0; // Mach threads    basic_info = (task_basic_info_t)tinfo;    // get threads in the task    kr = task_threads(mach_task_self(), &thread_list, &thread_count);    if (kr != KERN_SUCCESS) {        return -1;    }    if (thread_count > 0)        stat_thread += thread_count;    long tot_sec = 0;    long tot_usec = 0;    float tot_cpu = 0;    int j;    for (j = 0; j < (int)thread_count; j++)    {        thread_info_count = THREAD_INFO_MAX;        kr = thread_info(thread_list[j], THREAD_BASIC_INFO,                         (thread_info_t)thinfo, &thread_info_count);        if (kr != KERN_SUCCESS) {            return -1;        }        basic_info_th = (thread_basic_info_t)thinfo;        if (!(basic_info_th->flags & TH_FLAGS_IDLE)) {            tot_sec = tot_sec + basic_info_th->user_time.seconds + basic_info_th->system_time.seconds;            tot_usec = tot_usec + basic_info_th->user_time.microseconds + basic_info_th->system_time.microseconds;            tot_cpu = tot_cpu + basic_info_th->cpu_usage / (float)TH_USAGE_SCALE * 100.0;        }    } // for each thread    kr = vm_deallocate(mach_task_self(), (vm_offset_t)thread_list, thread_count * sizeof(thread_t));    assert(kr == KERN_SUCCESS);    return tot_cpu;}

71、float数据取整四舍五入

 CGFloat f = 4.65;    NSLog(@"%d", (int)f);    // 打印结果4    CGFloat f = 4.65;    NSLog(@"%d", (int)round(f));    // 打印结果5

72、删除UISearchBar系统默认边框

    // 方法一    searchBar.searchBarStyle = UISearchBarStyleMinimal;    // 方法二    [searchBar setBackgroundImage:[[UIImage alloc]init]];    // 方法三    searchBar.barTintColor = [UIColor whiteColor];

73、为UICollectionViewCell设置圆角和阴影

cell.contentView.layer.cornerRadius = 2.0f;cell.contentView.layer.borderWidth = 1.0f;cell.contentView.layer.borderColor = [UIColor clearColor].CGColor;cell.contentView.layer.masksToBounds = YES;cell.layer.shadowColor = [UIColor lightGrayColor].CGColor;cell.layer.shadowOffset = CGSizeMake(0, 2.0f);cell.layer.shadowRadius = 2.0f;cell.layer.shadowOpacity = 1.0f;cell.layer.masksToBounds = NO;cell.layer.shadowPath = [UIBezierPath bezierPathWithRoundedRect:cell.bounds cornerRadius:cell.contentView.layer.cornerRadius].CGPath;

74、让正在滑动的scrollView停止滚动(不是禁止,而是暂时停止滚动)

[scrollView setContentOffset:scrollView.contentOffset animated:NO];

75、使用xib设置UIView的边框、圆角

圆角和边框看下图即可设置

这里写图片描述

xib设置圆角边框.png

但是增加layer.borderColor的keyPath设置边框颜色并不能起作用,后来查了资料,这里应该用layer.borderUIColor,但是这里设置的颜色不起作用,无论设置什么颜色显示出来的都是黑色的。后来又去查了下,有种解决方案是给CALayer添加一个分类,提供一个 - (void)setBorderUIColor:(UIColor *)color;方法就可以解决了,实现如下:
这里写图片描述

xib设置边框颜色.png

#import "CALayer+BorderColor.h"@implementation CALayer (BorderColor)- (void)setBorderUIColor:(UIColor *)color{    self.borderColor = color.CGColor;}

76、根据经纬度获取城市等信息

// 创建经纬度    CLLocation *location = [[CLLocation alloc] initWithLatitude:latitude longitude:longitude];    //创建一个译码器    CLGeocoder *cLGeocoder = [[CLGeocoder alloc] init];    [cLGeocoder reverseGeocodeLocation:userLocation completionHandler:^(NSArray *placemarks, NSError *error) {        CLPlacemark *place = [placemarks objectAtIndex:0];        // 位置名      NSLog(@"name,%@",place.name);      // 街道      NSLog(@"thoroughfare,%@",place.thoroughfare);      // 子街道      NSLog(@"subThoroughfare,%@",place.subThoroughfare);      // 市      NSLog(@"locality,%@",place.locality);      // 区      NSLog(@"subLocality,%@",place.subLocality);       // 国家      NSLog(@"country,%@",place.country);        }    }];/*  CLPlacemark中属性含义name                    地名thoroughfare            街道subThoroughfare        街道相关信息,例如门牌等locality                城市subLocality            城市相关信息,例如标志性建筑administrativeArea      直辖市subAdministrativeArea  其他行政区域信息(自治区等)postalCode              邮编ISOcountryCode          国家编码country                国家inlandWater            水源,湖泊ocean                  海洋areasOfInterest        关联的或利益相关的地标*/

77、如何防止添加多个NSNotification观察者?

// 解决方案就是添加观察者之前先移除下这个观察者[[NSNotificationCenter defaultCenter] removeObserver:observer name:name object:object];        [[NSNotificationCenter defaultCenter] addObserver:observer selector:selector name:name object:object];

78、将一个xib添加到另外一个xib上

// 假设你的自定义view名字为CustomView,你需要在CustomView.m中重写 `- (instancetype)initWithCoder:(NSCoder *)aDecoder` 方法,代码如下:- (instancetype)initWithCoder:(NSCoder *)aDecoder {    if ((self = [super initWithCoder:aDecoder])) {        [self addSubview:[[[NSBundle mainBundle] loadNibNamed:@"CustomView" owner:self options:nil] objectAtIndex:0]];    }    return self;}

将一个xib添加到另外一个xib上.png

79、处理字符串,使其首字母大写

   NSString *str = @"abcdefghijklmn";    NSString *resultStr;    if (str && str.length > 0) {        resultStr = [str stringByReplacingCharactersInRange:NSMakeRange(0,1) withString:[[str substringToIndex:1] capitalizedString]];    }    NSLog(@"%@", resultStr);

80、判断一个UIAlertView/UIAlertController是否显示

// UIAlertView自带属性if (alert.visible){      NSLog(@"显示了");} else {      NSLog(@"未显示");}// UIAlertController没有visible属性,需要自己判断,添加一个全局变量 BOOL visibleUIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Title" message:@"message" preferredStyle:UIAlertControllerStyleAlert];    UIAlertAction *alertAction = [UIAlertAction actionWithTitle:@"ActionTitle" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {        self.visible = NO;    }];    UIAlertAction *calcelAction = [UIAlertAction actionWithTitle:@"calcelTitle" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {        self.visible = NO;    }];    [alertController addAction:alertAction];    [alertController addAction:calcelAction];    [self presentViewController:alertController animated:YES completion:^{        self.visible = YES;    }];

81、获取字符串中的数字

- (NSString *)getNumberFromStr:(NSString *)str{    NSCharacterSet *nonDigitCharacterSet = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];    return [[str componentsSeparatedByCharactersInSet:nonDigitCharacterSet] componentsJoinedByString:@""];}    NSLog(@"%@", [self getNumberFromStr:@"a0b0c1d2e3f4fda8fa8fad9fsad23"]); // 00123488923

82、为UIView的某个方向添加边框

// 添加UIView分类// UIView+WZB.h#import/** 边框方向 - WZBBorderDirectionTop: 顶部 - WZBBorderDirectionLeft: 左边 - WZBBorderDirectionBottom: 底部 - WZBBorderDirectionRight: 右边 */typedef NS_ENUM(NSInteger, WZBBorderDirectionType) {    WZBBorderDirectionTop = 0,    WZBBorderDirectionLeft,    WZBBorderDirectionBottom,    WZBBorderDirectionRight};@interface UIView (WZB)/** 为UIView的某个方向添加边框 @param direction 边框方向 @param color 边框颜色 @param width 边框宽度 */- (void)wzb_addBorder:(WZBBorderDirectionType)direction color:(UIColor *)color width:(CGFloat)width;@end// UIView+WZB.m#import "UIView+WZB.h"@implementation UIView (WZB)- (void)wzb_addBorder:(WZBBorderDirectionType)direction color:(UIColor *)color width:(CGFloat)width{    CALayer *border = [CALayer layer];    border.backgroundColor = color.CGColor;    switch (direction) {        case WZBBorderDirectionTop:        {            border.frame = CGRectMake(0.0f, 0.0f, self.bounds.size.width, width);        }            break;        case WZBBorderDirectionLeft:        {            border.frame = CGRectMake(0.0f, 0.0f, width, self.bounds.size.height);        }            break;        case WZBBorderDirectionBottom:        {            border.frame = CGRectMake(0.0f, self.bounds.size.height - width, self.bounds.size.width, width);        }            break;        case WZBBorderDirectionRight:        {            border.frame = CGRectMake(self.bounds.size.width - width, 0, width, self.bounds.size.height);        }            break;        default:            break;    }    [self.layer addSublayer:border];}

83、通过属性设置UISwitch、UIProgressView等控件的宽高

mySwitch.transform = CGAffineTransformMakeScale(5.0f, 5.0f);progressView.transform = CGAffineTransformMakeScale(5.0f, 5.0f);

84、自动搜索功能,用户连续输入的时候不搜索,用户停止输入的时候自动搜索(我这里设置的是0.5s,可根据需求更改)

// 输入框文字改变的时候调用-(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText{    // 先取消调用搜索方法    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(searchNewResult) object:nil];    // 0.5秒后调用搜索方法    [self performSelector:@selector(searchNewResult) withObject:nil afterDelay:0.5];}

85、修改UISearchBar的占位文字颜色

  // 方法一(推荐使用)    UITextField *searchField = [searchBar valueForKey:@"_searchField"];    [searchField setValue:[UIColor blueColor] forKeyPath:@"_placeholderLabel.textColor"];    // 方法二(已过期)    [[UILabel appearanceWhenContainedIn:[UISearchBar class], nil] setTextColor:[UIColor redColor]];    // 方法三(已过期)    NSDictionary *placeholderAttributes = @{NSForegroundColorAttributeName : [UIColor redColor], NSFontAttributeName : [UIFont fontWithName:@"HelveticaNeue" size:15],};    NSAttributedString *attributedPlaceholder = [[NSAttributedString alloc] initWithString:searchBar.placeholder attributes:placeholderAttributes];    [[UITextField appearanceWhenContainedIn:[UISearchBar class], nil] setAttributedPlaceholder:attributedPlaceholder];

86、某个界面多个事件同时响应引起的问题(比如,两个button同时按push到新界面,两个都会响应,可能导致push重叠)

// UIView有个属性叫做exclusiveTouch,设置为YES后,其响应事件会和其他view互斥(有其他view事件响应的时候点击它不起作用)view.exclusiveTouch = YES;// 一个一个设置太麻烦了,可以全局设置[[UIView appearance] setExclusiveTouch:YES];// 或者只设置button[[UIButton appearance] setExclusiveTouch:YES];

87、修改tabBar的frame

// 子类化UITabBarViewController,我这里以修改tabBar高度为例,重写viewWillLayoutSubviews方法#import "WZBTabBarViewController.h"@interface WZBTabBarViewController ()@end@implementation WZBTabBarViewController- (void)viewWillLayoutSubviews {    CGRect tabFrame = self.tabBar.frame;    tabFrame.size.height = 100;    tabFrame.origin.y = self.view.frame.size.height - 100;    self.tabBar.frame = tabFrame;}@end

88、修改键盘背景颜色

// 设置某个键盘颜色    textField.keyboardAppearance = UIKeyboardAppearanceAlert;// 设置工程中所有键盘颜色[[UITextField appearance] setKeyboardAppearance:UIKeyboardAppearanceAlert];

89、修改image颜色

UIImage *image = [UIImage imageNamed:@"test"];    imageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];    CGRect rect = CGRectMake(0, 0, image.size.width, image.size.height);    UIGraphicsBeginImageContext(rect.size);    CGContextRef context = UIGraphicsGetCurrentContext();    CGContextClipToMask(context, rect, image.CGImage);    CGContextSetFillColorWithColor(context, [[UIColor redColor] CGColor]);    CGContextFillRect(context, rect);    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    UIImage *flippedImage = [UIImage imageWithCGImage:img.CGImage scale:1.0 orientation: UIImageOrientationDownMirrored];    imageView.image = flippedImage;

90、动画执行removeFromSuperview

 [UIView animateWithDuration:0.2                     animations:^{                         view.alpha = 0.0f;                     } completion:^(BOOL finished){                         [view removeFromSuperview];                     }];

91、设置UIButton高亮背景颜色

[UIView animateWithDuration:0.2
                  animations:^{                         view.alpha = 0.0f;                     } completion:^(BOOL finished){                         [view removeFromSuperview];                     }];

92、设置UIButton高亮时的背景颜色

// 方法一、子类化UIButton,重写setHighlighted:方法,代码如下#import "WZBButton.h"@implementation WZBButton- (void)setHighlighted:(BOOL)highlighted {    [super setHighlighted:highlighted];    UIColor *normalColor = [UIColor greenColor];    UIColor *highlightedColor = [UIColor redColor];    self.backgroundColor = highlighted ? highlightedColor : normalColor;}// 方法二、利用setBackgroundImage:forState:方法[button setBackgroundImage:[self imageWithColor:[UIColor blueColor]] forState:UIControlStateHighlighted];- (UIImage *)imageWithColor:(UIColor *)color {    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);    UIGraphicsBeginImageContext(rect.size);    CGContextRef context = UIGraphicsGetCurrentContext();    CGContextSetFillColorWithColor(context, [color CGColor]);    CGContextFillRect(context, rect);    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    return image;}

93、关于图片拉伸

推荐看这个博客,讲的很详细:http://blog.csdn.net/q199109106q/article/details/8615661

94、利用runtime获取一个类所有属性

- (NSArray *)allPropertyNames:(Class)aClass{    unsigned count;    objc_property_t *properties = class_copyPropertyList(aClass, &count);    NSMutableArray *rv = [NSMutableArray array];    unsigned i;    for (i = 0; i < count; i++)    {        objc_property_t property = properties[i];        NSString *name = [NSString stringWithUTF8String:property_getName(property)];        [rv addObject:name];    }    free(properties);    return rv;}

95、设置textView的某段文字变成其他颜色

- (void)setupTextView:(UITextView *)textView text:(NSString *)text color:(UIColor *)color {    NSMutableAttributedString *string = [[NSMutableAttributedString alloc]initWithString:textView.text];    [string addAttribute:NSForegroundColorAttributeName value:color range:[textView.text rangeOfString:text]];    [textView setAttributedText:string];}

96、让push跳转动画像modal跳转动画那样效果(从下往上推上来)

- (void)push{TestViewController *vc = [[TestViewController alloc] init];    vc.view.backgroundColor = [UIColor redColor];    CATransition* transition = [CATransition animation];    transition.duration = 0.4f;    transition.type = kCATransitionMoveIn;    transition.subtype = kCATransitionFromTop;    [self.navigationController.view.layer addAnimation:transition forKey:kCATransition];    [self.navigationController pushViewController:vc animated:NO];}- (void)pop{CATransition* transition = [CATransition animation];    transition.duration = 0.4f;    transition.type = kCATransitionReveal;    transition.subtype = kCATransitionFromBottom;    [self.navigationController.view.layer addAnimation:transition forKey:kCATransition];    [self.navigationController popViewControllerAnimated:NO];}

97、上传图片太大,压缩图片

-(UIImage *)resizeImage:(UIImage *)image{    float actualHeight = image.size.height;    float actualWidth = image.size.width;    float maxHeight = 300.0;    float maxWidth = 400.0;    float imgRatio = actualWidth/actualHeight;    float maxRatio = maxWidth/maxHeight;    float compressionQuality = 0.5;//50 percent compression    if (actualHeight > maxHeight || actualWidth > maxWidth)    {        if(imgRatio < maxRatio)        {            //adjust width according to maxHeight            imgRatio = maxHeight / actualHeight;            actualWidth = imgRatio * actualWidth;            actualHeight = maxHeight;        }        else if(imgRatio > maxRatio)        {            //adjust height according to maxWidth            imgRatio = maxWidth / actualWidth;            actualHeight = imgRatio * actualHeight;            actualWidth = maxWidth;        }        else        {            actualHeight = maxHeight;            actualWidth = maxWidth;        }    }    CGRect rect = CGRectMake(0.0, 0.0, actualWidth, actualHeight);    UIGraphicsBeginImageContext(rect.size);    [image drawInRect:rect];    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();    NSData *imageData = UIImageJPEGRepresentation(img, compressionQuality);    UIGraphicsEndImageContext();    return [UIImage imageWithData:imageData];}

98,二维码生成和扫描
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