在 TextBlock 的绑定文本中更改子字符串的颜色 [英] Changing the colors of substrings within the bound Text of a TextBlock
问题描述
我正在将一些属性绑定到我的 TextBlock
:
I am binding some property into my TextBlock
:
<TextBlock
Text="{Binding Status}"
Foreground="{Binding RealTimeStatus,Converter={my:RealTimeStatusToColorConverter}}"
/>
Status
是简单的文本,RealTimeStatus
是 enum
.对于每个 enum
值,我正在更改我的 TextBlock
Foreground
颜色.
Status
is simple text and RealTimeStatus
is enum
. For each enum
value I am changing my TextBlock
Foreground
color.
有时我的 Status
消息包含数字.该消息根据 enum
值获得适当的颜色,但我想知道是否可以更改此消息中数字的颜色,这样数字的颜色将与文本的其余部分不同.
Sometimes my Status
message contains numbers. That message gets the appropriate color according to the enum
value, but I wonder if I can change the colors of the numbers inside this message, so the numbers will get different color from the rest of the text.
编辑.
XAML
<TextBlock my:TextBlockExt.XAMLText="{Binding Status, Converter={my:RealTimeStatusToColorConverter}}"/>
转换器:
public class RealTimeStatusToColorConverter : MarkupExtension, IValueConverter
{
// One way converter from enum RealTimeStatus to color.
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
if (value is RealTimeStatus && targetType == typeof(Brush))
{
switch ((RealTimeStatus)value)
{
case RealTimeStatus.Cancel:
case RealTimeStatus.Stopped:
return Brushes.Red;
case RealTimeStatus.Done:
return Brushes.White;
case RealTimeStatus.PacketDelay:
return Brushes.Salmon;
default:
break;
}
}
return null;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
public RealTimeStatusToColorConverter()
{
}
// MarkupExtension implementation
public override object ProvideValue(IServiceProvider serviceProvider)
{
return this;
}
}
推荐答案
这里有一个附加属性,可以将任意文本解析为 XAML TextBlock
内容,包括 Run
、Span
、Bold
等.这具有普遍有用的优点.
Here's an attached property which parses arbitrary text as XAML TextBlock
content, including Run
, Span
, Bold
, etc. This has the advantage of being generally useful.
我建议您编写一个 ValueConverter
用适当的标记替换 Status
文本中的数字,这样当你给它这个文本时......
I recommend you write a ValueConverter
which replaces the numbers in your Status
text with appropriate markup, such that when you give it this text...
错误编号 34:猴子小猫没有奶油冻.
Error number 34: No custard for monkey kitty.
...它将把它转换成这个文本:
...it would convert that into this text:
错误编号 <Span Foreground="Red">34</Span>:猴子小猫没有奶油冻.
Error number <Span Foreground="Red">34</Span>: No custard for monkey kitty.
您已经知道如何进行值转换器,使用正则表达式进行文本替换是完全不同的主题.
You already know how to do value converters, and text substitution with regular expressions is a different subject entirely.
XAML 用法:
<TextBlock
soex:TextBlockExt.XAMLText={Binding Status, Converter={my:redNumberConverter}}"
/>
如果是我,我会疯狂地将颜色设为 ConverterParameter.
If it were me I'd go hog wild and make the color a ConverterParameter.
这是该附加属性的 C#:
Here's the C# for that attached property:
using System;
using System.IO;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
namespace StackOverflow.Examples
{
public static class TextBlockExt
{
public static String GetXAMLText(TextBlock obj)
{
return (String)obj.GetValue(XAMLTextProperty);
}
public static void SetXAMLText(TextBlock obj, String value)
{
obj.SetValue(XAMLTextProperty, value);
}
/// <summary>
/// Convert raw string from ViewModel into formatted text in a TextBlock:
///
/// @"This <Bold>is a test <Italic>of the</Italic></Bold> text."
///
/// Text will be parsed as XAML TextBlock content.
///
/// See WPF TextBlock documentation for full formatting. It supports spans and all kinds of things.
///
/// </summary>
public static readonly DependencyProperty XAMLTextProperty =
DependencyProperty.RegisterAttached("XAMLText", typeof(String), typeof(TextBlockExt),
new PropertyMetadata("", XAMLText_PropertyChanged));
private static void XAMLText_PropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (d is TextBlock)
{
var ctl = d as TextBlock;
try
{
// XAML needs a containing tag with a default namespace. We're parsing
// TextBlock content, so make the parent a TextBlock to keep the schema happy.
// TODO: If you want any content not in the default schema, you're out of luck.
var strText = String.Format(@"<TextBlock xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation"">{0}</TextBlock>", e.NewValue);
TextBlock parsedContent = System.Windows.Markup.XamlReader.Load(GenerateStreamFromString(strText)) as TextBlock;
// The Inlines collection contains the structured XAML content of a TextBlock
ctl.Inlines.Clear();
// UI elements are removed from the source collection when the new parent
// acquires them, so pass in a copy of the collection to iterate over.
ctl.Inlines.AddRange(parsedContent.Inlines.ToList());
}
catch (Exception ex)
{
System.Diagnostics.Trace.WriteLine(String.Format("Error in Ability.CAPS.WPF.UIExtensions.TextBlock.XAMLText_PropertyChanged: {0}", ex.Message));
throw;
}
}
}
public static Stream GenerateStreamFromString(string s)
{
MemoryStream stream = new MemoryStream();
StreamWriter writer = new StreamWriter(stream);
writer.Write(s);
writer.Flush();
stream.Position = 0;
return stream;
}
}
}
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