Comments on: RichTextBox syntax highlighting

By: Vlad

Vlad — Tue, 13 Oct 2009 06:29:28 +0000

Here is one alternative solution: http://blog.bodurov.com/Wpf-Source-Code-Editor

By: vlad

vlad — Sat, 10 Oct 2009 00:52:02 +0000

By the way why are you using bitwise or | instead of conditional or ||? For example here Char.IsWhiteSpace(text[i]) | JSSyntaxProvider.GetSpecials.Contains(text[i]) This will evaluate the second expression even if the first is true. If you use || and the first is true (character is white space) it will not waste time to look at the second. Obviously character cannot be white space and special at the same time

By: Alan Smith

Alan Smith — Mon, 12 Jan 2009 16:26:51 +0000

For anyone landing here looking for WPF Richtextbox syntax highlighting, I can confirm that the above is not a solution for any meaningful size of file. I previously used ScintillaNet for this purpose but cannot get it working under 64bit Vista. Having decided I only need some basic highlighting and not folding, block comment colouring etc I am experimenting (with some success) a more efficient version of the above concept.
Perhaps more determined and capable programmers than me might find this concept worth exploring….
1. Concept …. Use the Paragraph.Tag flags in the document to indicate that a paragraph needs highlighting or re-highlighting… use NULL (the default) to indicate it does need highlighting that way newly pasted text is handled.
2. In the TextChangedEventHandler use the change list (with the Event Arg e) to mark each unique paragraph mentioned as needing re-highlighting follows…
foreach (TextChange C in e.Changes)
{
TextPointer P = Document.ContentStart.GetPositionAtOffset(C.Offset);
if (P.Paragraph != null) P.Paragraph.Tag = null; //It needs reformatting
}
ReformatAsNeeded()
3. Call reformat as needed at the end of the Text change event and when the file is first loaded (this bit is slow)
void ReformatAsNeeded()
{
if (Document.Blocks.Count > 0)
{
Block B = Document.Blocks.FirstBlock;
while (B != null)
{
if (B is Paragraph)
{
Paragraph P = B as Paragraph;
if (P.Tag == null)
{
ReFormat(P);
P.Tag = true; //It has been highlighted
}
}
else throw new Exception(“Unknown block type ” + B.ToString());
B = B.NextBlock;
}
}

4. Modify the “navigator” code in the article to only walk the Paragraph supplied via the Reformat call shown above.
Initial highlighting a newly loaded file is still slow (it probably always will be using this technology!) but I can live with that for my files. As said this is experimental work in progress, it may not work… is probably too early to mention, but posting now as it may trigger ideas. Yes I know there are still bugs in it (from the original) like does not colour a word on the end of line.

PS – Please excuse the possible poor formatting.

By: Tamir Khason

Tamir Khason — Thu, 01 Jan 2009 08:03:22 +0000

it’s low what?

By: bs

bs — Thu, 01 Jan 2009 08:03:20 +0000

great sample–just what i was looking for, thanks

By: 陈锋

陈锋 — Thu, 01 Jan 2009 08:03:19 +0000

RichTextBox 中文字背景高亮方法的一些link

By: Rajesh Kumar

Rajesh Kumar — Thu, 01 Jan 2009 08:03:17 +0000

You don't need to define something called "Tag". You can use TextRange instead, which serves for the same.

See this sample: blogs.msdn.com/.../navigate-words-in-richtextbox.aspx

By: Pavol

Pavol — Thu, 01 Jan 2009 08:03:16 +0000

Good work, but it's so horribly slow…

By: Pavol

Pavol — Thu, 01 Jan 2009 08:03:15 +0000

this is the row: that slow things down:

documentRange.ClearAllProperties();

By: Tom

Tom — Thu, 01 Jan 2009 08:03:14 +0000

Try instead of documentRange.ClearAllProperties();

just set the background and foreground colors of the whole FlowDocument to white and black