兼容Silverlight4的实用的Silverlight可拖放工具类源代码

2016-08-20 10:53:37来源:http://dotfun.blog.51cto.com/663391/286060作者:dotfun人点击


开发日常的Silverlight应用程序时,常常要对一个域多个控件实现可拖放的MOUSE操作,在Silverlight中实现拖放的功能其实非常简单,但是为了提高程序功能代码的可复用性,程序员常常喜欢把常用的代码封装成一个工具类,例如Asp.net中常用SQLHelper类,用来操作数据库的,这里我们介绍的类是在Silverlight中实现拖动的工具类,它支持Silverlight2.0至Silverlight4.0的各个版本通用,好了话不多说,我们还是看代码吧:
public static class DragDrop{ private static bool IsDragging = false; private static Point curPoint; private const int MAX_ZINDEX = 99999; private const double CURRENT_OPACITY = 0.5; private static int lastZIndex; private static double lastOpacity;
private static void sender_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) { UIElement uiElement = sender as UIElement; if (uiElement != null) { uiElement.CaptureMouse(); lastZIndex = (int)uiElement.GetValue(Canvas.ZIndexProperty); uiElement.SetValue(Canvas.ZIndexProperty, MAX_ZINDEX); lastOpacity = uiElement.Opacity; uiElement.Opacity = CURRENT_OPACITY; IsDragging = true; curPoint = new Point(e.GetPosition(null).X, e.GetPosition(null).Y); } }
private static void sender_MouseMove(object sender, MouseEventArgs e) { if (!IsDragging) { return; }
UIElement uiElement = sender as UIElement; if (uiElement != null) { double currentLeft = (double)uiElement.GetValue(Canvas.LeftProperty); double currentTop = (double)uiElement.GetValue(Canvas.TopProperty);
double newLeft = (double)currentLeft + e.GetPosition(null).X - curPoint.X; double newTop = (double)currentTop + e.GetPosition(null).Y - curPoint.Y;
uiElement.SetValue(Canvas.LeftProperty, newLeft); uiElement.SetValue(Canvas.TopProperty, newTop); curPoint = new Point(e.GetPosition(null).X, e.GetPosition(null).Y); } }
private static void sender_MouseLeftButtonUp(object sender, MouseButtonEventArgs e) { UIElement uiElement = sender as UIElement; if (uiElement != null) { uiElement.ReleaseMouseCapture(); IsDragging = false; uiElement.SetValue(Canvas.ZIndexProperty, lastZIndex); uiElement.Opacity = lastOpacity; } }
public static void Load(UIElement sender) { sender.MouseLeftButtonDown += new MouseButtonEventHandler(sender_MouseLeftButtonDown); sender.MouseLeftButtonUp += new MouseButtonEventHandler(sender_MouseLeftButtonUp); sender.MouseMove += new MouseEventHandler(sender_MouseMove); }
public static void UnLoad(UIElement sender) { sender.MouseLeftButtonDown -= new MouseButtonEventHandler(sender_MouseLeftButtonDown); sender.MouseLeftButtonUp -= new MouseButtonEventHandler(sender_MouseLeftButtonUp); sender.MouseMove -= new MouseEventHandler(sender_MouseMove); }}
DragDrop工具类的使用方法:DragDrop.Load(LayoutRoot);DragDrop是一个静态类,使用起来非常简单,以上只要一行代码就可以实现对Grid控件的拖放操作了。希望对大家有所帮助~!

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