解决popup不随着window一起移动的问题

参考：

http://stackoverflow.com/questions/1600218/how-to-move-a-wpf-popup

http://social.msdn.microsoft.com/Forums/zh-CN/wpfzhchs/thread/2616e607-3954-4bfd-ae29-e0d813263030

给窗口加一个“LocationChanged”事件，然后在这个事件中做如下处理：

private void window_LocationChanged(object sender, EventArgs e)

{

    this.TestPopup.ClearValue(Popup.IsOpenProperty);

    this.TestPopup.IsOpen = true;

}

public MainWindow()

{

 LocationChanged += new EventHandler(MainWindow_LocationChanged);

 }

 

void MainWindow_LocationChanged(object sender, EventArgs e)

{

//参考链接1

var mi = typeof(Popup).GetMethod("UpdatePosition", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);

mi.Invoke(popBottom, null);

 

//此方法容易导致 闪烁

//popBottom.ClearValue(Popup.IsOpenProperty);

 //popBottom.IsOpen = true;

}

 方法2：转载于Leaco 的博客http://www.cnblogs.com/Leaco/p/3168540.html

public class PopopHelper
    {
        public static DependencyObject GetPopupPlacementTarget(DependencyObject obj)
        {
            return (DependencyObject)obj.GetValue(PopupPlacementTargetProperty);
        }

        public static void SetPopupPlacementTarget(DependencyObject obj, DependencyObject value)
        {
            obj.SetValue(PopupPlacementTargetProperty, value);
        }

        // Using a DependencyProperty as the backing store for PopupPlacementTarget.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty PopupPlacementTargetProperty =
            DependencyProperty.RegisterAttached("PopupPlacementTarget", typeof(DependencyObject), typeof(PopopHelper), new PropertyMetadata(null,OnPopupPlacementTargetChanged));

        private static void OnPopupPlacementTargetChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if (e.NewValue != null)
            {
                DependencyObject popupPopupPlacementTarget = e.NewValue as DependencyObject;
                Popup pop = d as Popup;

                Window w = Window.GetWindow(popupPopupPlacementTarget);
                if (null != w)
                {
                    w.LocationChanged += delegate
                    {
                        var offset = pop.HorizontalOffset;
                        pop.HorizontalOffset = offset + 1;
                        pop.HorizontalOffset = offset;
                    };
                }
            }
        }
        
    }

然后在Popup控件上这样写即可：

<Grid>
        <TextBox x:Name="placementTextBox"/>
       <Popup PopopHelper.PopupPlacementTarget="{Binding ElementName=placementTextBox}" />
   </Grid>