绑定按钮能见度在视图模型bool值 [英] Binding a Button Visibility to bool value in ViewModel

问题描述

我想一个按钮的可见性绑定到我的视图模型一个布尔值。
我怎样才能做到这一点？我看见有几个类似的问题在这里＃2，但没有得到正是我想要的。

我有这个，但我怎么能绑定到我的虚拟机一个bool。

 ＆LT;按钮
 HEIGHT =50WIDTH =50
 风格={StaticResource的MyButtonStyle}
 命令={结合SmallDisp}CommandParameter ={结合}
光标=手能见度={绑定路径= AdvancedFormat}/＆GT;
 

解决方案

假设 AdvancedFormat 是布尔，你需要声明并使用<一个href=\"http://msdn.microsoft.com/en-us/library/system.windows.controls.booleantovisibilityconverter%28v=vs.110%29.aspx\"><$c$c>BooleanToVisibilityConverter:

 ＆LT;！ - 在XAML你的资源部分 - ＆GT;
＆LT; BooleanToVisibilityConverter X：键=BoolToVis/＆GT;＆LT;！ - 在你的按钮声明 - ＆GT;
＆LT;按钮
 HEIGHT =50WIDTH =50
 风格={StaticResource的MyButtonStyle}
 命令={结合SmallDisp}CommandParameter ={结合}
光标=手能见度={绑定路径= AdvancedFormat，转换器= {StaticResource的BoolToVis}}/＆GT;
 

请注意添加 =转换器的StaticResource {} BoolToVis 。

这与MVVM工作时是一个很常见的模式。从理论上讲，你可以做的视图模型属性自己的转换（即只是做类型的物业本身能见度），虽然我会preFER不这样做，因为现在您的是的与关注点分离搞乱。一个项目的visbility确实应该到视图。

I want to bind the visibility of a button to a bool value in my ViewModel. How can I accomplish this? I saw a couple of similar questions here on Stackoverflow but didn't get exactly what I wanted.

I have this but how can I bind it to a bool in my VM.

<Button
 Height="50" Width="50"
 Style="{StaticResource MyButtonStyle}"
 Command="{Binding SmallDisp}" CommandParameter="{Binding}" 
Cursor="Hand" Visibility="{Binding Path=AdvancedFormat}"/>

解决方案

Assuming AdvancedFormat is a bool, you need to declare and use a BooleanToVisibilityConverter:

<!-- In your resources section of the XAML -->
<BooleanToVisibilityConverter x:Key="BoolToVis" />

<!-- In your Button declaration -->
<Button
 Height="50" Width="50"
 Style="{StaticResource MyButtonStyle}"
 Command="{Binding SmallDisp}" CommandParameter="{Binding}" 
Cursor="Hand" Visibility="{Binding Path=AdvancedFormat, Converter={StaticResource BoolToVis}}"/>

Note the added Converter={StaticResource BoolToVis}.

This is a very common pattern when working with MVVM. In theory you could do the conversion yourself on the ViewModel property (i.e. just make the property itself of type Visibility) though I would prefer not to do that, since now you are messing with the separation of concerns. An item's visbility should really be up to the View.

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