未检测到变量以绑定 UWP 中的可见性属性

Question

我有三个按钮，我想用一个变量来调节它们的可见性。但是我的印象是没有检测到我的变量。

MainPage.xaml :

<Button
    Margin="0,0,0,50"
    Name="startButton"
    Height="50"
    Width="250"
    Click="OnStartClick"
    ClickMode="Press"
    Visibility="{Binding StartVisibility, Converter={StaticResource BoolToVisibilityConverter}}">
    Start
</Button>
<Button
    Margin="0,0,0,50"
    Name="validButton"
    Height="50"
    Width="250"
    Click="OnValidClick"
    ClickMode="Press"
    Visibility="{Binding ValidVisibility, Converter={StaticResource BoolToVisibilityConverter}}">
    Valid
</Button>
<Button 
    Margin="0,50,0,0"
    Name="stopButton"
    Height="50"
    Width="250"
    Click="OnStopClick"
    ClickMode="Press"
    Visibility="{Binding StopVisibility, Converter={StaticResource BoolToVisibilityConverter}, Mode=OneWay}">
    Cancel
</Button>

MainPage.xaml.cs :

private IMapService _mapService;
private bool drawing = false;

public bool StopVisibility
{
    get
    {
         return drawing;
    }
}

public bool StartVisibility
{
    get
    {
         return !drawing;
    }
}

public bool ValidVisibility
{
    get
    {
         return _mapService.SketchEditorCanExecute();
    }
}

IMapService.cs :

bool SketchEditorCanExecute();

BoolToVisibilityConverter.cs :

public object Convert(object value,
                      Type targetType,
                      object parameter,
                      String language)
{
    Boolean val = false;
    if (value is Boolean)
    {
        val = (Boolean)value;
    }
    return val
        ? Visibility.Visible
        : Visibility.Collapsed;
}

有了断点，我发现我从来没有通过 Get 方法。转换器也有同样的问题。

有什么想法吗？

Answer 1

您可能忘记设置 DataContext。

您可以在代码隐藏或 XAML

中设置 DataContext

代码隐藏

public class MainPage.xaml
{
    public MainPage()
    {
        this.DataContext = this;
        InitializeComponent();
    }
}

在XAML

<MainPage DataContext="{Binding RelativeSource={RelatativeSource Self}}" />

未检测到变量以绑定 UWP 中的可见性属性

Variable not detected to binding visibility properties in UWP

c#

xaml

binding

visibility

converters