我想启用Drag'n'Drop的一个父控制器,它有一个IsManipulationEnabled = true
。WPF Drag&Drop vs操作
当启用操作时,触摸事件不会升级为鼠标事件。为了启用升级,您应该在操作逻辑步骤之前处理触摸事件(请参阅example)。我已经尝试过,它的工作原理......直到我第一次拨打DoDragDrop
。然后我不再接收鼠标事件。为什么?
下面是重现此问题的最低代码。为了便于阅读,删除了所有拖放操作。
XAML:
<Window x:Class="Test.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="300" Width="300" IsManipulationEnabled="True">
<Grid>
<Border Background="Red"
x:Name="Border"
TouchDown="Border_OnTouchDown"
MouseDown="Border_OnMouseDown"
TouchUp="Border_OnTouchUp"
Width="100" Height="50" />
</Grid>
</Window>
C#:
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
}
private void Border_OnTouchDown(object sender, TouchEventArgs e)
{
Debug.WriteLine("Border_OnTouchDown");
e.Handled = true;
e.TouchDevice.Capture((FrameworkElement)sender);
}
private void Border_OnMouseDown(object sender, MouseButtonEventArgs e)
{
Debug.WriteLine("Border_OnMouseDown!");
DragDrop.DoDragDrop((DependencyObject)sender, "", DragDropEffects.All);
}
protected override void OnManipulationStarted(ManipulationStartedEventArgs e)
{
Debug.WriteLine("OnManipulationStarted");
base.OnManipulationStarted(e);
}
private void Border_OnTouchUp(object sender, TouchEventArgs e)
{
((FrameworkElement)sender).ReleaseTouchCapture(e.TouchDevice);
e.Handled = true;
}
}
输出:
Border_OnTouchDown
Border_OnMouseDown! <- works first time
Border_OnTouchDown
Border_OnTouchDown <- no longer works, no matter how many times I tap
Border_OnTouchDown
Border_OnTouchDown
Border_OnTouchDown
...
如果我不叫DoDragDrop
在MouseDown
- 事件得到提升,因为他们应该。