WPF命令绑定-如何到达事件处理程序

Hi Is there any way to choose from where XAML should use command bindings event handlers? I added copule of command binding to my cusotm control, however functions which are resonsible for execute and can_execute are not directly in code behind but in another class. This class is derived from Canvas and I create instance of this class in XAML.

Hi，有什么方法可以选择XAML应该使用命令绑定事件处理程序吗?我添加了对我的cusotm控件的命令绑定，但是对于执行和can_execute的功能来说，它们并不是直接在代码后面，而是在另一个类中。这个类派生自Canvas，我在XAML中创建该类的实例。

<s:MyCanvas  Focusable="true"  Background="Transparent" x:Name="OwnCanvas" FocusVisualStyle="{x:Null}" ScrollViewer.CanContentScroll="True" >

I add command bindings this way

我以这种方式添加命令绑定

<UserControl.CommandBindings>
    <CommandBinding Command="{x:Static ApplicationCommands.Copy}" CanExecute="event handler from object OwnCanvas" />
</UserControl.CommandBindings>

Is there any way to do that ? Or I have to transfer event handler directly to codebehind ??

有什么办法吗?还是必须将事件处理程序直接传输到codebehind ?

1 个解决方案

#1

I think you're gonna have to transfer the handler in codebehind as I don't think that's possible. I could be wrong and would love to be corrected if it is possible though.

我认为你必须在codebehind中转移处理器，因为我认为这是不可能的。我可能是错的，如果可能的话，我希望被纠正。

What I usually do is just define the CommandBinding in your MyCanvas class (code behind) and then reference that MyCanvas as the CommandTarget in the custom control. Like this:

我通常做的是在MyCanvas类(代码后面)中定义CommandBinding，然后在自定义控件中引用MyCanvas作为CommandTarget。是这样的:

    public MyCanvas()
    {
        ...

        CommandBindings.Add(
            new CommandBinding(ApplicationCommands.Copy,
                (sender, e) => {
                    // Execute Stuff
                },
                (sender, e) => {
                    e.CanExecute = true; 
                    e.Handled = true; 
                }));
        ...
    }

And in your custom control (given it lies within the visual tree of MyCanvas)...

在您的自定义控件(给定它位于MyCanvas的可视树中)…

<Button Command="{x:Static ApplicationCommands.Copy}" CommandTarget="{Binding RelativeSource={RelativeSource AncestorType={x:Type s:MyCanvas}}}"/>

With your CommandTarget set up like that the Execute and CanExecute methods will be called on it.

使用您的CommandTarget设置，就会调用Execute和CanExecute方法。

#1