How to change the format of specified strings in RichTextBox

Question

I have winforms RichTextBox containing many lines of text (e.g. 2 MB text files) and would like to programmatically change the formatting of the specified lines, for example, select them.

How can I address strings, not characters? Is RichTextBox even the best control for this kind of thing, or is there another alternative? I tried Infragistics UltraFormattedTextEditor, but it was several orders of magnitude slower to display text, so nothing good for my longer files.

Thanks!

Answer 1

To access strings in text field controls, you use the Lines property

richTextBox.Lines

From there you can iterate over the lines and work with the ones you want to change.

Edit: I agree, I skipped the highlighted part (+1 to answer your own question). Including working code:

int lineCounter = 0; foreach(string line in richTextBox1.Lines) { //add conditional statement if not selecting all the lines richTextBox.Select(richTextBox.GetFirstCharIndexFromLine(lineCounter), line.Length); richTextBox.SelectionColor = Color.Red; lineCounter++; } 

Answer 2

OK, I will document the solution I found: using richTextBox.Lines to get the rows, as Louis says, then

 richTextBox.GetFirstCharIndexFromLine(int line) richTextBox.Select(int start, int length) 

to select the appropriate rows, then

 richTextBox.SelectionColor... richTextBox.SelectionBackground... 

etc .. etc to format strings.