了解 WPF 绑定 CommandParameter="{Binding}"; [英] Understand WPF Binding CommandParameter="{Binding}"

问题描述

也许这是一个愚蠢的问题，但我找不到答案:在下面的 xaml 中，CommandParameter 绑定到什么?或者一般来说，"{Binding}" 是什么意思?

Maybe this is a dumb question, but I can't find the answer: in the following xaml what does CommandParameter binding to? Or in general, what does "{Binding}" mean?

<Button Command="{Binding DataContext.DeleteCommand, ElementName=List}" 
        CommandParameter="{Binding}"/>

推荐答案

{Binding ...} 是一个 MarkupExtension.
在其通常的形式中，它采用类似 {Binding Path=someProperty, ...} 的 Path(或其缩写形式 {Binding someProperty, ...}).
所以 {Binding} 中的路径是空的，这意味着 Binding 绑定到任何用于 Binding 的 Source.如果您知道 {Binding} 实际上与 {Binding DataContext,RelativeSource={RelativeSource Self}} 相同，这可能更容易理解.

{Binding ...} is a MarkupExtension.
In its usual form it takes a Path like {Binding Path=someProperty, ...} (or its short form {Binding someProperty, ...}).
So the path in {Binding} is empty which means the Binding is bound to whatever Source there is for the Binding. This might be a little easier to understand if you know, that {Binding} is actually the same as {Binding DataContext,RelativeSource={RelativeSource Self}}.

因此，在您的情况下，CommandParameter 获取按钮的当前 DataContext 的值.

So in your case CommandParameter gets the value of the current DataContext of the Button.

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