Question

我试图仅在bool ListBoxItem为真时才显示isInEditMode。这是我的变量：

private bool isInEditMode
{
    get { return Convert.ToBoolean(GetValue(IsInEditMode_Property)); }
    set { SetValue(IsInEditMode_Property, value); }
}

public static readonly DependencyProperty IsInEditMode_Property = DependencyProperty.Register("isInEditMode", typeof(bool), typeof(MainWindow), new PropertyMetadata(null));

这是我添加ListBoxItem：

的地方

SurfaceListBoxItem slbi = new SurfaceListBoxItem();    

Binding visibilityBinding = new Binding("Visibility");
visibilityBinding.Source = isInEditMode;
visibilityBinding.Converter = new BoolToVisibility();
visibilityBinding.NotifyOnTargetUpdated = true;
slbi.SetBinding(SurfaceListBoxItem.VisibilityProperty, visibilityBinding);                    

myListBox.Items.Add(slbi);

然而，当更改isInEditMode时，转换器没有被触发。什么地方出了错？这是我的转换器btw，非常直接：

public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
    if (System.Convert.ToBoolean(value) == true)
        return System.Windows.Visibility.Visible;
    else
        return System.Windows.Visibility.Collapsed;
}

我在XAML中进行了快速测试，但这有效：

<Grid Visibility="{Binding Path=isInEditMode, ElementName=myMainWindow, Converter={StaticResource BoolToVisibility}, NotifyOnTargetUpdated=True}" />

Answer 1

您构建Binding是错误的。 Source是对象，即绑定操作的数据源。 Path（您通过ctor参数设置它）是数据源中数据属性的路径。

因此，Binding应如下所示：

var visibilityBinding = new Binding("isInEditMode");
visibilityBinding.Source = this;
visibilityBinding.Converter = new BoolToVisibility();
visibilityBinding.NotifyOnTargetUpdated = true;

// here you setting the target property - VisibilityProperty
slbi.SetBinding(SurfaceListBoxItem.VisibilityProperty, visibilityBinding);

在代码中绑定到变量和转换器

1 个答案: