WPF Popup实现拖动

2016-11-24 12:41:00来源:CSDN作者:wcc27857285人点击

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问题一.popup总是置顶,遮挡其他窗口


最近发现popup设置打开后,总是会遮挡其他窗口,而我们只想让它仅仅在应用程序的上一层即可,并不像让它在最上面

解决方案是继承Popup重新定义控件PopupEx。

public class PopupEx : Popup    {        public static DependencyProperty TopmostProperty = Window.TopmostProperty.AddOwner(typeof(PopupEx ), new FrameworkPropertyMetadata(false, OnTopmostChanged));        public bool Topmost        {            get { return (bool)GetValue(TopmostProperty); }            set { SetValue(TopmostProperty, value); }        }        private static void OnTopmostChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)        {            (obj as PopupEx ).UpdateWindow();        }        protected override void OnOpened(EventArgs e)        {            UpdateWindow();        }        private void UpdateWindow()        {            var hwnd = ((HwndSource)PresentationSource.FromVisual(this).Handle;            RECT rect;            if (GetWindowRect(hwnd, out rect))            {                SetWindowPos(hwnd, Topmost ? -1 : -2, rect.Left, rect.Top, (int)this.Width, (int)this.Height, 0);            }        }        #region imports definitions        [StructLayout(LayoutKind.Sequential)]        public struct RECT        {            public int Left;            public int Top;            public int Right;            public int Bottom;        }        [DllImport("user32.dll")]        [return: MarshalAs(UnmanagedType.Bool)]        private static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect);        [DllImport("user32", EntryPoint = "SetWindowPos")]        private static extern int SetWindowPos(IntPtr hWnd, int hwndInsertAfter, int x, int y, int cx, int cy, int wFlags);        #endregion    }

然后在调用该控件的时候设置该PopupEx的属性 Topmost=False即可。


以上方法来自 Leaco 的博客:http://www.cnblogs.com/Leaco


但是,呵呵,然并软,在new该popupEx的时侯设置topmost=false之后,还是会置顶

后来再加上了一句代码即可解决这个问题:就是在将popupEx加入到某个panel或者父容器当中,因为popup的parent的只读的,无法赋值,

所以我就让一个dockpanel.Children.Add(popupEx),配合PopupEx类,就完美解决了该问题。



************2016.11.16******************************

问题二.popup无法跟随主窗体移动或者更新状态

后来发现这个popup随着窗体移动不会消失,网上流传的方法就是在主窗体的locationchanged事件和sizechanged事件里面

回调一个函数,代码如下:

  Loaded += (sender, e) =>
              {
                  Window window = Window.GetWindow(this);
                  window.LocationChanged += HandleMovePopup;
                  window.SizeChanged += HandleMovePopup;
              };

 void HandleMovePopup(object sender, EventArgs e)
        {
            if (NewMsgPop != null && NewMsgPop.IsOpen)
            {
                var mi = typeof(Popup).GetMethod("UpdatePosition", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
                mi.Invoke(NewMsgPop, null);
            }
        }
是可以解决这个移动窗体的问题。然并软,还有更坑爹的事情,当程序不在最顶部,既有其他应用程序在最顶部时,

此时再让popup.isopen=true时,还是会显示在其他应用程序之前。。。。。。。。。。

真是欲哭无泪,最后的解决方案是:改成一个label, 通过设置Gird.SetZindex(label,0)或者Gird.SetZindex(label,2)来控制label的显隐。

前提是将label放进一个Grid里面

至此,这个功能需求算是圆满完成了,留给我的启发是,以后能不用popup尽量不用。。。。。。。


当然肯定有办法能解决这个问题,迫于项目压力,没有时间去细究,

当然如果有高人能说出更厉害的方法来解决这个问题,希望能赐教!



************2016.11.24******************************

问题三:Popup如何拖动

有几个思路,第一,是得到鼠标位置,然后通过API发消息给popup通知其修改自己的位置,第二是在mousemove事件里直接修改popup的位置。

第一种方法可参考该博客:http://www.cnblogs.com/lisweden/p/3183476.html

然后介绍第二种方法:

要引用 system.windows.itneractivity.dll

然后新建class

  public class popup_dragmove_behavior : Behavior<Popup>    {        public bool _mouse_down;        Point _old_pos;        Point _orignal_pos;        double max_vertical_offset;        public popup_dragmove_behavior()        {        }        protected override void OnAttached()        {            base.OnAttached();            AssociatedObject.MouseLeftButtonDown += (sender, e) =>            {                mouse_left_button_down(sender, e);            };            AssociatedObject.MouseLeftButtonUp += (sender, e) =>            {                mouse_left_button_up(sender, e);            };            AssociatedObject.MouseMove += (sender, e) =>            {                mouse_move(sender, e);            };            AssociatedObject.Closed += (sender, e) =>            {                popup_close(sender, e);            };        }        protected override void OnDetaching()        {            base.OnDetaching();            AssociatedObject.MouseLeftButtonDown -= (sender, e) =>            {                mouse_left_button_down(sender, e);            };            AssociatedObject.MouseLeftButtonUp -= (sender, e) =>            {                mouse_left_button_up(sender, e);            };            AssociatedObject.MouseMove -= (sender, e) =>            {                mouse_move(sender, e);            };            AssociatedObject.Closed -= (sender, e) =>            {                popup_close(sender, e);            };        }        void mouse_left_button_down(Object sender, MouseButtonEventArgs e)        {            _mouse_down = true;            if (AssociatedObject.VerticalOffset == 0)            {                _orignal_pos = AssociatedObject.Child.PointToScreen(new Point(AssociatedObject.ActualWidth, 0));                max_vertical_offset = 0 - _orignal_pos.Y;            }            _old_pos = AssociatedObject.Child.PointToScreen(e.GetPosition(AssociatedObject.Child));            AssociatedObject.Child.CaptureMouse();        }        void mouse_move(Object sender, MouseEventArgs e)        {            if (!_mouse_down)            {                return;            }            var child_pos = e.GetPosition(AssociatedObject.Child);            var new_pos = AssociatedObject.Child.PointToScreen(child_pos);            var offset = new_pos - _old_pos;            _old_pos = new_pos;            AssociatedObject.HorizontalOffset += offset.X;            var new_VerticalOffset = AssociatedObject.VerticalOffset + offset.Y;            if (new_VerticalOffset < max_vertical_offset)            {                new_VerticalOffset = max_vertical_offset;            }            AssociatedObject.VerticalOffset = new_VerticalOffset;        }        void mouse_left_button_up(Object sender, MouseButtonEventArgs e)        {            _mouse_down = false;            AssociatedObject.Child.ReleaseMouseCapture();        }        void popup_close(Object sender, EventArgs e)        {            AssociatedObject.HorizontalOffset = 0;            AssociatedObject.VerticalOffset = 0;        }    }



然后这样调用即可:

popup_dragmove_behavior  b=new popup_dragmove_behavior();

b.attch(your_popup);


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