当我使用 <control>.ContextMenu.IsOpen = true
打开上下文菜单时, 上下文菜单变为可见但打开或关闭事件均未触发。
我怎样才能确保 ContextMenuOpening
和 ContextMenuClosing
当我以编程方式打开上下文菜单时会引发事件?
演示:
看下面的XAML
<Button Name="ContextMenuButton"
Content="Click me!"
Click="ContextMenuButton_Click"
ContextMenuOpening="ContextMenuButton_OnContextMenuOpening"
ContextMenuClosing="ContextMenuButton_OnContextMenuClosing">
<Button.ContextMenu>
<ContextMenu>
<MenuItem Header="First element" />
<MenuItem Header="Second element" />
</ContextMenu>
</Button.ContextMenu>
</Button>
以及下面的代码隐藏
public MainWindow() // Constructor
{
InitializeComponent();
ContextMenuButton.ContextMenuOpening += (sender, args) => Debug.Print("Opening #2");
ContextMenuButton.ContextMenuClosing += (sender, args) => Debug.Print("Closing #2");
}
private void ContextMenuButton_Click(object sender, RoutedEventArgs e)
{
Button button = (sender as Button);
button.ContextMenu.IsOpen = true; // How should I open the ContextMenu?
}
private void ContextMenuButton_OnContextMenuOpening(object sender, ContextMenuEventArgs e)
{
Debug.Print("Opening #1");
}
private void ContextMenuButton_OnContextMenuClosing(object sender, ContextMenuEventArgs e)
{
Debug.Print("Closing #1");
}
右键单击按钮时的行为:
上下文菜单正在打开。
输出是:
Opening #1
Opening #2
Closing #1
Closing #2
左键单击按钮时的行为:
上下文菜单正在打开。
输出是:
<Nothing>
最佳答案
问题是您已经在 Button 的 ContextMenuOpening 上附加了事件,并且由于您是手动调用 ContextMenu,所以事件没有触发
所以要从 ContextMenu 中附加 Opened 和 Closed 事件来获取事件
public MainWindow() // Constructor
{
InitializeComponent();
ContextMenuButton.ContextMenu.Opened += (sender, args) => Debug.Print("Opening #2");
ContextMenuButton.ContextMenu.Closed += (sender, args) => Debug.Print("Closing #2");
}
xaml
<Button Name="ContextMenuButton"
Content="Click me!"
Click="ContextMenuButton_Click" >
<Button.ContextMenu>
<ContextMenu Opened="ContextMenuButton_OnContextMenuOpening" Closed="ContextMenuButton_OnContextMenuClosing">
<MenuItem Header="First element" />
<MenuItem Header="Second element" />
</ContextMenu>
</Button.ContextMenu>
</Button>
事件,ContextMenuEventArgs 改为 RoutedEventArgs
private void ContextMenuButton_OnContextMenuOpening(object sender, RoutedEventArgs e)
{
Debug.Print("Opening #1");
}
private void ContextMenuButton_OnContextMenuClosing(object sender, RoutedEventArgs e)
{
Debug.Print("Closing #1");
}
按钮点击保持不变。
这应该可以解决您的问题
关于c# - 以编程方式打开上下文菜单时如何引发 ContextMenuOpening 事件,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/24083786/