突出显示文本的RichTextBox [英] Highlight text in RichTextBox

问题描述

我试图用一个RichTextBox和我的第一感觉：什么是它的复杂使用...
最好的...

I'm trying to use a RichTextBox and my first feeling : "What's it's complicated to use !"... Amazing ...

所以我想强调包含在我的RichTextBox的文本

So I'm trying to highlight a text contained in my RichTextBox.

目前，我有以下代码：

TextRange range = new TextRange(MyTextInput.Document.ContentStart, MyTextInput.Document.ContentEnd);
range.Text = @"TOP a multiline text or file END";
Regex reg = new Regex("(top|file|end)", RegexOptions.Compiled | RegexOptions.IgnoreCase);

foreach (Match match in reg.Matches(range.Text))
{
    TextPointer start = range.Start.GetPositionAtOffset(match.Index, LogicalDirection.Forward);
    TextPointer end = range.Start.GetPositionAtOffset(match.Index + match.Length, LogicalDirection.Backward);
    // text contains the exact match I want
    string text = range.Text.Substring(match.Index, match.Length);
    // here the highlighted text isn't the text I searched...
    TextRange textrange = new TextRange(start, end);
    textrange.ApplyPropertyValue(TextElement.ForegroundProperty, new SolidColorBrush(Colors.Blue));
    textrange.ApplyPropertyValue(TextElement.FontWeightProperty, FontWeights.Bold);
}

TOP 是正确的突出但不文件或结束，但突出了我或。

TOP is correctly highlighted but not file or end but highlight me or.

有什么建议？

推荐答案

你必须想象在RichTextBox引擎盖下不理解的行为。我并不确切地知道，但我想象中的以下内容：第1-2行集与的RichTextBox A 段落内容一个运行。

you have to imagine what the RichTextBox does under the hood to understand the behavior. I don't know exactly but I imagine the following: Line 1-2 set as Content of RichTextBox a Paragraph with a Run.

然后用 ApplyPropertyValue 在RichTextBox的内容得到改变！现在，它包含一个段落与跨度（用运行中）和运行。

Then with the first iteration with ApplyPropertyValue the Content of the RichTextBox gets changed! It now contains a Paragraph with a Span (with a Run inside) and a Run.

然后你必须要考虑的正则表达式匹配之间的差异 GetPositionAtOffset 。正则表达式匹配返回字符串中的一个字符位置的索引。

And then you have to consider the discrepancy between the Regex match and GetPositionAtOffset. The Regex match returns an index for a char position in a string.

GetPositionAtOffset 用途的 一个偏移量的符号，要计算并返回的位置的，其中一个标志是：

GetPositionAtOffset uses "An offset, in symbols, for which to calculate and return the position" where a symbol is:

• 为元素的TextElement打开或关闭标签。


• 包含在InlineUIContainer或BlockUIContainer一个的UIElement元素。需要注意的是这样的的UIElement总是算作正好一个符号;通过的UIElement包含的任何额外的内容或元素不作为符号。


• 一个16位的Unicode字符的文本运行元素中。

所以，你可能想要做的是这样的：

So what you might want to do is something like this:

TextRange range = new TextRange(MyTextInput.Document.ContentStart, MyTextInput.Document.ContentEnd);
range.Text = @"TOP a multiline text or file END";
Regex reg = new Regex("(top|file|end)", RegexOptions.Compiled | RegexOptions.IgnoreCase);

var start = MyTextInput.Document.ContentStart;
while (start != null && start.CompareTo(MyTextInput.Document.ContentEnd) < 0)
{
    if (start.GetPointerContext(LogicalDirection.Forward) == TextPointerContext.Text)
    {
        var match=reg.Match(start.GetTextInRun(LogicalDirection.Forward));

        var textrange = new TextRange(start.GetPositionAtOffset(match.Index, LogicalDirection.Forward), start.GetPositionAtOffset(match.Index + match.Length, LogicalDirection.Backward));
        textrange.ApplyPropertyValue(TextElement.ForegroundProperty, new SolidColorBrush(Colors.Blue));
        textrange.ApplyPropertyValue(TextElement.FontWeightProperty, FontWeights.Bold);
        start= textrange.End; // I'm not sure if this is correct or skips ahead too far, try it out!!!
    }
    start = start.GetNextContextPosition(LogicalDirection.Forward);
}

*免责声明：我没有尝试过这是现在我隔靴搔痒一个开发环境。我甚至不知道这是否编译，但我希望如此。

*Disclaimer: I have not tried this as right now I'm nowhere near a development environment. I don't even know if this compiles, but I hope so.

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