WPF 文字换行TextWrapping 显示不全用省略号TextTrimming 显示不全弹提示内容ToolTip

Posted 2021-02-02 lonelyxmas

原文:WPF 文字换行TextWrapping 显示不全用省略号TextTrimming 显示不全弹提示内容ToolTip

【TextBlock】

换行? ? TextWrapping="Wrap"

内容显示不全时显示省略号，如 “AAA...”? ??TextTrimming="CharacterEllipsis" //以单词边界做截断

鼠标提示? ?<ToolTip>

?

例：??

TextBlock不允许换行，超出后显示省略号截断，超出的情况鼠标移上去会弹出提示内容。

?①? .xaml

<!--xaml 内容不允许换行，显示不下用省略号-->
<TextBlock TextTrimming="CharacterEllipsis" Width="150" TextWrapping="NoWrap" Text="AAAA">
    <TextBlock.ToolTip>
        <ToolTip Style="{DynamicResource TooltipStyle}" Content="BBB"/>
    </TextBlock.ToolTip>
</TextBlock>

?② ToolTip样式定义

属性Visibility绑定转换器，仅当内容显示不全时弹出

<Style x:Key="TooltipStyle" TargetType="{x:Type ToolTip}">
                <Setter Property="MaxWidth" Value="228"/>
                <Setter Property="BorderThickness" Value="0"/>
                <Setter Property="Background" Value="#FF565656"/>
                <Setter Property="FontFamily" Value="{DynamicResource BaseFontFamily}"/>
                <Setter Property="FontSize" Value="14"/>
                <Setter Property="Foreground" Value="#FFFFFFFF"/>
                <!--内容显示不全时弹出-->
                <Setter Property="Visibility" Value="{Binding RelativeSource={RelativeSource Self}, Path=PlacementTarget, Converter={StaticResource TrimToolTipConverter}}"/>
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type ToolTip}">
                            <Border CornerRadius="4" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}">
                                <TextBlock Padding="8,4" Margin="0,-1,0,0" TextWrapping="Wrap" FontFamily="{TemplateBinding FontFamily}" FontSize="{TemplateBinding FontSize}"
                                           Foreground="{TemplateBinding Foreground}" Text="{TemplateBinding Content}">
                                </TextBlock>
                            </Border>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>

?

?③ Converter转换器

判断TextBlock是否启用Trim属性（内容显示不下），启用了则ToolTip可视

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Media;

namespace ui.DataConverter
{
        /// <summary>
        /// 文字显示不下通过ToolTip提示显示
        /// </summary>
        public class TrimmedTextBlockVisibilityConverter : IValueConverter
        {
            public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
            {
                if (value == null)
                {
                    return Visibility.Collapsed;
                }

                TextBlock textBlock = (TextBlock)value;
                bool isTrim = IsTextTrimmed(textBlock);

                if (isTrim)
                {
                    return Visibility.Visible;
                }
                else
                {
                    return Visibility.Collapsed;
                }
            }

            public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
            {
                throw new NotImplementedException();
            }

            /// <summary>
            /// 判断当前显示的内容是否显示不全被截断
            /// </summary>
            /// <param name="textBlock"></param>
            /// <returns></returns>
            private bool IsTextTrimmed(TextBlock textBlock)
            {
                Typeface typeface = new Typeface(
                    textBlock.FontFamily,
                    textBlock.FontStyle,
                    textBlock.FontWeight,
                    textBlock.FontStretch);

                FormattedText formattedText = new FormattedText(
                    textBlock.Text,
                    System.Threading.Thread.CurrentThread.CurrentCulture,
                    textBlock.FlowDirection,
                    typeface,
                    textBlock.FontSize,
                    textBlock.Foreground); 
                bool isTrimmed = formattedText.Width > textBlock.Width;
                return isTrimmed;
            }
        }
}

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