理解WPF Binding CommandParameter ="{Binding}"

Question

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}"意味着什么？

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

Answer 1

{Binding ...}是MarkupExtension.
在其通常的形式中,它采用路径{Binding Path=someProperty, ...}(或其简短形式{Binding someProperty, ...}).
所以路径{Binding}是空的,这意味着绑定绑定到绑定的任何源.如果你知道,这可能会更容易理解,这{Binding}实际上是相同的{Binding DataContext,RelativeSource={RelativeSource Self}}.

因此,在您的情况下,CommandParameter获取Button的当前DataContext的值.

Answer 2

Empty {Binding}将分别将控件的当前DataContext传递给Executed和CanExecute方法.

检查以下链接

http://www.developmentalmadness.com/archive/2009/08/26/xaml-binding-to-the-current-datacontext.aspx

http://www.wpfmentor.com/2009/01/how-to-add-binding-to-commandparameter.html