TextTrimming 属性不适用于自定义 TextBlock

Question

我创建了一个 "bindable" TextBlock，即绑定到项目的文本块，这些项目具有定义文本呈现方式的属性（颜色，例如).

但是，'TextTrimming' 属性不适用于我的自定义文本块，代码如下：

class BindableTextBlock : TextBlock
{
    public BindableTextBlock()
    {

    }

    public bool HideWhenEmpty
    {
        get { return (bool)GetValue(HideWhenEmptyProperty); }
        set { SetValue(HideWhenEmptyProperty, value); }
    }

    public static readonly DependencyProperty HideWhenEmptyProperty =
        DependencyProperty.Register("HideWhenEmpty", typeof(bool), typeof(BindableTextBlock), new UIPropertyMetadata(false));

    public ObservableCollection<DescriptionToken> Items
    {
        get { return (ObservableCollection<DescriptionToken>)GetValue(ItemsProperty); }
        set { SetValue(ItemsProperty, value); }
    }

    public static readonly DependencyProperty ItemsProperty =
        DependencyProperty.Register("Items", typeof(ObservableCollection<DescriptionToken>), typeof(BindableTextBlock), new UIPropertyMetadata(null, OnItemsPropertyChanged));

    private static void OnItemsPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        ((BindableTextBlock)d).OnItemsChanged();
    }

    private void OnItemsChanged()
    {
        if (Items == null)
            return;
        Items.CollectionChanged -= ItemsCollectionChanged;
        Items.CollectionChanged += ItemsCollectionChanged;

        BuildText();
    }

    private void BuildText()
    {
        Inlines.Clear();
        if (Items == null || !Items.Any())
        {
            if (HideWhenEmpty)
                Visibility = System.Windows.Visibility.Collapsed;
            return;
        }

        for (var i = 0; i < Items.Count; i++)
        {
            var item = Items[i];
            var run = new Run(TruncateText(item.Text));
            if (item.IsVariable)
            {
                run.Foreground = new SolidColorBrush(item.IsError ? Colors.Red : Colors.Blue);
                run.FontStyle = FontStyles.Italic;
            }
            Inlines.Add(run);
        }

        Visibility = System.Windows.Visibility.Visible;
        InvalidateVisual();
    }

    private string TruncateText(string text)
    {
        if (string.IsNullOrEmpty(text))
            return text;

        if (text.Contains(Environment.NewLine))
            return TruncateText(text.Substring(0, text.IndexOf(Environment.NewLine)) + "...");

        if (text.Length > 120)
        {
            var result = text.Substring(0, 120).TrimEnd('.');
            return result + "...";
        }

        return text;
    }

    private void ItemsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        BuildText();
    }

每当 Items 发生变化时，它都会操纵 TextBlock.Inlines 以设置文本颜色。

XAML

<DataTemplate>
 <Border Padding="3">
            <StackPanel Grid.Column="1" Orientation="Vertical">

                <TextBlock Text="aaaaaaa aaaaaaaaaa aaaaaaaaaaaaa bbbbbb cccccccccc ddddddddddd eeeeeeeeeeeeeeee ffffffffffffffffff ggggggggggg" FontStyle="Italic" FontSize="10" TextTrimming="CharacterEllipsis"/>
                <controls:BindableTextBlock Items="{Binding Description}" FontSize="10"
                                            FontStyle="Italic" HideWhenEmpty="True"
                                            TextTrimming="CharacterEllipsis"/>
            </StackPanel>
        </Border>
       </DataTemplate>

下图显示第一个 TextBlock 被修剪了，但第二个（我的）没有：

如何使我的自定义 TextBlock 像常规 TextBlock 一样工作 TextTrimming 属性？

Answer 1

如果您的控件换行，则不能 trim。所以删除这段代码：

TextWrapping = System.Windows.TextWrapping.Wrap;

来自控件的构造函数。

TextTrimming 属性不适用于自定义 TextBlock

TextTrimming property does not work for a custom TextBlock

c#

wpf

xaml

custom-controls

TextTrimming 属性 不适用于自定义 TextBlock

TextTrimming property does not work for a custom TextBlock

c#

wpf

xaml

custom-controls

TextTrimming 属性不适用于自定义 TextBlock