如何将命令绑定到 MenuItem (WPF)? [英] How do you bind a command to a MenuItem (WPF)?

问题描述

这是我在 View.xaml.cs 中的代码:

Here is my code from the View.xaml.cs:

private RelayCommand _closeCommand;
public ICommand CloseCommand
{
    get
    {
        if (_closeCommand == null)
        {
            _closeCommand = new RelayCommand(param => this.OnClose());
        }
        return _closeCommand;
    }
}

public void OnClose()
{
    Close();
}

这是我的 View.xaml 中的一些代码:

And here is some code from my View.xaml:

<Window.ContextMenu>
    <ContextMenu>
        <MenuItem Name="menuItem_Close" Header="Close" Command="{Binding CloseCommand}" />
    </ContextMenu> 
</Window.ContextMenu>

当我运行程序并选择关闭菜单项时，什么也没有发生.CloseCommand 代码甚至没有被执行.

When I run the program and select the close menu item, nothing happens. The CloseCommand code doesn't even get executed.

推荐答案

ContextMenu 不是 VisualTree 的一部分，这就是 DataContext 不会被继承的原因.这里 ContextMenu.PlacementTarget 是获取 Window 的某种中继:

ContextMenu is not part of the VisualTree, that's why the DataContext will not be inherited. Here ContextMenu.PlacementTarget is some kind of relay to get the Window:

<MenuItem Name="menuItem_Close" Header="Close"
          Command="{Binding Path=PlacementTarget.DataContext.CloseCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}" />

这篇关于如何将命令绑定到 MenuItem (WPF)?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！