如何突出显示列表框中的匹配子字符串? [英] How to highlight matching sub-strings inside a ListBox?

问题描述

我有一个文本框和一个列表框来搜索一组数据.在列表框中搜索文本时，如果在列表中的任何位置找到匹配的字符串，它应该以绿色和粗体显示.

I have one TextBox and one listbox for searching a collection of data. While searching a text inside a Listbox if that matching string is found anywhere in the list it should show in Green color with Bold.

例如.我有像这样的字符串集合依赖属性、自定义属性、普通属性".如果我在搜索文本框中输入prop"，那么所有三个带有prop"(只有单词 Prop)的都应该是粗体并且它的颜色应该是绿色的.知道怎么做吗?

eg. I have string collection like "Dependency Property, Custom Property, Normal Property". If I type in the Search Text box "prop" all the Three with "prop" (only the word Prop) should be in Bold and its color should be in green. Any idea how it can be done?.

列表框中的数据使用 DataTemplate 表示.

Data inside listbox is represented using DataTemplate.

推荐答案

我创建了一个 HighlightTextBehavior，您可以将其附加到列表项模板中的 TextBlock(您需要添加对 System.Windows.Interactivity 的引用到你的项目).您将行为绑定到包含要突出显示的文本的属性，然后它会完成其余的工作.

I've created a HighlightTextBehavior that you can attach to a TextBlock within your list item templates (you'll need to add a reference to System.Windows.Interactivity to your project). You bind the behavior to a property containing the text you want to highlight, and it does the rest.

目前，它只突出显示字符串的第一个实例.它还假定文本没有应用其他格式.

At the moment, it only highlights the first instance of the string. It also assumes that there is no other formatting applied to the text.

using System.Linq;
using System.Text;
using System.Windows.Interactivity;
using System.Windows.Controls;
using System.Windows;
using System.Windows.Documents;
using System.Windows.Media;

namespace StringHighlight
{
    public class HighlightTextBehavior : Behavior<TextBlock>
    {
        public string HighlightedText
        {
            get { return (string)GetValue(HighlightedTextProperty); }
            set { SetValue(HighlightedTextProperty, value); }
        }

        // Using a DependencyProperty as the backing store for HighlightedText.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty HighlightedTextProperty =
            DependencyProperty.Register("HighlightedText", typeof(string), typeof(HighlightTextBehavior), new UIPropertyMetadata(string.Empty, HandlePropertyChanged));

        private static void HandlePropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
        {
            (sender as HighlightTextBehavior).HandlePropertyChanged();
        }

        private void HandlePropertyChanged()
        {
            if (AssociatedObject == null)
            {
                return;
            }

            var allText = GetCompleteText();

            AssociatedObject.Inlines.Clear();

            var indexOfHighlightString = allText.IndexOf(HighlightedText);

            if (indexOfHighlightString < 0)
            {
                AssociatedObject.Inlines.Add(allText);
            }
            else
            {
                AssociatedObject.Inlines.Add(allText.Substring(0, indexOfHighlightString));
                AssociatedObject.Inlines.Add(new Run() { 
                    Text = allText.Substring(indexOfHighlightString, HighlightedText.Length), 
                    Foreground = Brushes.Green,
                    FontWeight = FontWeights.Bold });
                AssociatedObject.Inlines.Add(allText.Substring(indexOfHighlightString + HighlightedText.Length));
            }
        }

        private string GetCompleteText()
        {
            var allText = AssociatedObject.Inlines.OfType<Run>().Aggregate(new StringBuilder(), (sb, run) => sb.Append(run.Text), sb => sb.ToString());
            return allText;
        }
    }
}

这是一个如何使用它的示例:

Here's an example of how you use it:

    <Window x:Class="StringHighlight.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
        xmlns:b="clr-namespace:StringHighlight"
        xmlns:sys="clr-namespace:System;assembly=mscorlib"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <Grid.Resources>
            <x:Array x:Key="MyStrings" Type="{x:Type sys:String}">
                <sys:String>This is my first string</sys:String>
                <sys:String>Another string</sys:String>
                <sys:String>A third string, equally imaginative</sys:String>
            </x:Array>
        </Grid.Resources>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <TextBox x:Name="SearchText"/>

        <ListBox Grid.Row="1" ItemsSource="{StaticResource MyStrings}">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock Grid.Row="1" Text="{Binding}">
                        <i:Interaction.Behaviors>
                            <b:HighlightTextBehavior HighlightedText="{Binding ElementName=SearchText, Path=Text}"/>
                        </i:Interaction.Behaviors>
                    </TextBlock>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
    </Grid>
</Window>

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