c# WPF DataGrid:如何在不破坏DataGrid本身的情况下为DataGrid单元格中的文本着色

经过一番谷歌搜索，我找到了另一种解决方案，在TextBlock内着色文本。我子类化了texblock，使它的InlineCollection可以通过一个新的RichText可绑定属性访问，然后编写了一个值转换器，将纯文本转换为基于正则表达式的富文本内联集合。

示例代码如下。

<Window x:Class="WPF.Tutorial.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:sys="clr-namespace:System;assembly=system"
        xmlns:local="clr-namespace:WPF.Tutorial"
        Title="MainWindow" Height="480" Width="640" WindowStartupLocation="CenterScreen">
    <Window.Resources>
        <local:RichTextValueConverter x:Key="RichTextValueConverter" />
    </Window.Resources>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition/>            
            <RowDefinition Height="30"/>
        </Grid.RowDefinitions>
        <DataGrid x:Name="testGrid" Grid.Row="0" AutoGenerateColumns="False" Background="White" CanUserAddRows="False" CanUserDeleteRows="False" Margin="2" SelectionUnit="FullRow" SelectionMode="Single">
            <DataGrid.Columns>
                <DataGridTextColumn Binding="{Binding Path=ID}" Header="ID" Width="30" IsReadOnly="True" />
                <DataGridTemplateColumn Header="Source" Width="*" IsReadOnly="True">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <local:RichTextBlock x:Name="sourceTextBlock" TextWrapping="Wrap" 
                                                 RichText="{Binding Path=SourceText, Converter={StaticResource RichTextValueConverter}}"  />
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>                    
                </DataGridTemplateColumn>
                <DataGridTemplateColumn Header="Target" Width="*">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <local:RichTextBlock x:Name="targetTextBlock" TextWrapping="Wrap" 
                                                 RichText="{Binding Path=TargetText, Converter={StaticResource RichTextValueConverter}}"/>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                    <DataGridTemplateColumn.CellEditingTemplate>
                        <DataTemplate>
                            <TextBox x:Name="targetTextBox" Text="{Binding Path=TargetText}" TextWrapping="Wrap" FocusManager.FocusedElement="{Binding RelativeSource={RelativeSource Self}}" />
                        </DataTemplate>
                    </DataGridTemplateColumn.CellEditingTemplate>
                </DataGridTemplateColumn>
            </DataGrid.Columns>
        </DataGrid>        
        <Label x:Name="statusLabel" Grid.Row="1" />
    </Grid>
</Window>

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Text.RegularExpressions;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Media;
using System.ComponentModel;
namespace WPF.Tutorial
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public static Regex SearchRegex = new Regex("(segment)", RegexOptions.IgnoreCase);
        public static Regex TagRegex = new Regex("(<[^>]*>)", RegexOptions.IgnoreCase);
        ObservableCollection<Segment> segments;
        public MainWindow()
        {
            InitializeComponent();
            segments = new ObservableCollection<Segment>();
            testGrid.ItemsSource = segments;
            for (int i = 1; i <= 100; i++)
            {
                segments.Add(new Segment()
                {
                    ID = i.ToString(),
                    SourceText = String.Format("Segment <b>{0}</b>", i),
                    TargetText = String.Format("Сегмент <b>{0}</b>", i)
                });
            }
            statusLabel.Content = String.Format("Items: {0}", testGrid.Items.Count);
        }

        public class Segment : IEditableObject
        {
            string targetBackup = null;
            public string ID { get; set; }
            public string SourceText { get; set; }
            public string TargetText { get; set; }
            public void BeginEdit()
            {
                if (targetBackup == null)
                    targetBackup = TargetText;
            }
            public void CancelEdit()
            {
                if (targetBackup != null)
                {
                    TargetText = targetBackup;
                    targetBackup = null;
                }
            }
            public void EndEdit()
            {
                if (targetBackup != null)
                    targetBackup = null;
            }
        }
    }

    public class RichTextBlock : TextBlock
    {
        public static DependencyProperty InlineProperty;
        static RichTextBlock()
        {
            //OverrideMetadata call tells the system that this element wants to provide a style that is different than in base class
            DefaultStyleKeyProperty.OverrideMetadata(typeof(RichTextBlock), new FrameworkPropertyMetadata(
                                typeof(RichTextBlock)));
            InlineProperty = DependencyProperty.Register("RichText", typeof(List<Inline>), typeof(RichTextBlock),
                            new PropertyMetadata(null, new PropertyChangedCallback(OnInlineChanged)));
        }
        public List<Inline> RichText
        {
            get { return (List<Inline>)GetValue(InlineProperty); }
            set { SetValue(InlineProperty, value); }
        }
        public static void OnInlineChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
        {
            if (e.NewValue == e.OldValue)
                return;
            RichTextBlock r = sender as RichTextBlock;
            List<Inline> i = e.NewValue as List<Inline>;
            if (r == null || i == null)
                return;
            r.Inlines.Clear();
            foreach (Inline inline in i)
            {
                r.Inlines.Add(inline);
            }
        }
    }

    class RichTextValueConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            string text = value as string;
            var inlines = new List<Inline>();
            if (text != null)
            {
                string[] pieces = MainWindow.TagRegex.Split(text);
                var subpieces = new List<string>();
                foreach (var piece in pieces)
                {
                    subpieces.AddRange(MainWindow.SearchRegex.Split(piece));
                }
                foreach (var item in subpieces)
                {
                    if (MainWindow.SearchRegex.Match(item).Success && !MainWindow.TagRegex.Match(item).Success)
                    {
                        Run runx = new Run(item);
                        runx.Background = Brushes.Yellow;
                        inlines.Add(runx);
                    }
                    else if (MainWindow.TagRegex.Match(item).Success)
                    {
                        Run runx = new Run(item);
                        runx.Foreground = Brushes.Red;
                        inlines.Add(runx);
                    }
                    else
                    {
                        inlines.Add(new Run(item));
                    }
                }
            }
            return inlines;
        }
        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException("Back conversion is not supported!");
        }
    }
}

现在颜色绘制在具有大量行的DataGrid上工作得很好。

p。一些来自MSDN论坛的人也建议将数据网格的VirtualizingPanel.IsVirtualizing属性设置为false。此解决方案适用于原始代码，但据我所知，此变体在性能方面不是很好。