在代碼中綁定到變量和轉換器

Question

我試圖使ListBoxItem僅在bool isInEditMode為true時出現。 這是我的變量：

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));

這是我添加ListBoxItem ：

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);

但是，更改isInEditMode時未觸發轉換器。 什么地方出了錯？ 這是我的轉換器，順便說一句：

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中進行了快速測試，但這可以工作：

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

Answer 1

您的Binding構造是錯誤的。 Source是對象，即綁定操作的數據源。 Path （通過ctor參數設置）是數據源中數據屬性的路徑。

因此， Binding應如下所示：

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);