使用BooleanToVisibilityConverter的WPF MVVM隐藏按钮 [英] WPF MVVM hiding button using BooleanToVisibilityConverter

问题描述

在WPF应用程序中，我试图根据用户选择的选项来更改按钮的可见性.加载时，我希望其中一个按钮不可见.我正在使用内置的值转换器BooleanToVisibilityConverter.但是，由于该按钮在加载时出现，因此无法正常工作.我将属性更改为true和false，没有区别.下面是我的代码，我看不到我缺少的东西吗?

In my WPF application I am trying to change the visibility of a button depending on the options chosen by a user. On load I want one of the buttons to not be visible. I am using the in built value converter BooleanToVisibilityConverter. However it's not working as the button is appearing at load time. I have changed the property to both true and false, makes no difference. Below is my code, I can't see what I'm missing?

我的视图模型中的属性

 bool ButtCancel
    {
        get { return _buttCancel; }
        set
        {
            _buttCancel = value;
            OnPropertyChanged("ButtCancel");
        }
    }

在我的app.xaml中

In my app.xaml

 <Application.Resources>       
    <BooleanToVisibilityConverter x:Key="BoolToVis"/>

在我的MainWindow.xaml中

In my MainWindow.xaml

 <Button Grid.Column="2" 
      Command="{Binding CommandButtProgressCancel}" 
      Content="Cancel" 
      Visibility="{Binding ButtCancel, Converter={StaticResource BoolToVis}}"
      IsEnabled="{Binding ButtCancelEnabled}" 
      Height="50" Width="120" 
      HorizontalAlignment="Center" 
      VerticalAlignment="Center" Margin="0,0,50,20"/>

推荐答案

对于初学者来说，如果您使用的是Command，则不需要绑定IsEnabled，命令实现应对此进行决定.

For starters mate, if you're using a Command, then you don't need to bind IsEnabled, the command implementation should decide this.

第二，将ViewModel绑定到View往往会在稍后阶段进行，因此最好也为该绑定设置一个默认值，就像这样

Secondly, the binding of a ViewModel to a View tends to happen at a bit of a later stage, so it's best to also set a default value for the binding, like so

Visibility="{Binding ButtCancel, Converter={StaticResource BoolToVis}, FallbackValue=Hidden}"

第三点，正如Mike指出的那样，请确保您的媒体资源是公开的，因为ViewModel和View是两个单独的类.

Third, as Mike pointed out, ensure that your property is public, since the ViewModel and the View are two separate classes.

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