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

问题描述

在我的 WPF 应用程序中，我试图根据用户选择的选项更改按钮的可见性.在加载时，我希望其中一个按钮不可见.我正在使用内置值转换器 BooleanToVisibilityConverter.但是它不起作用，因为按钮在加载时出现.我已将属性更改为 true 和 false，没有区别.下面是我的代码，我看不到我遗漏了什么?

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，如果你使用的是 Command，那么你不需要绑定 IsEnabled，这应该由命令实现来决定.

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

其次，ViewModel 与 View 的绑定往往发生在稍晚的阶段，所以最好也为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，正如 Mike 所指出的，确保您的属性是公开的，因为 ViewModel 和 View 是两个独立的类.

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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