Suspend and resume layout only affect resizing and redrawing of controls, from what I got out of my experimenting with it this afternoon.

It turns out, the original method using the RichTextBox.Find is still faster than the char-by-char method, but not because of calculation time.. The actual char by char writing to the RichTextBox, whether visible, disabled, suspended, or not, is incredibly slow.

I can load a huge file into the RTB in almost no time using standard streamreader read methods, but char by char it's way too slow. I did some testing with my parsing method, and if I use special characters to define where colors would stop and start, rather than actually coloring/writing them to the RTB, and write that string to the RTB all in black, the text loads at what is not noticably any slower speed.

Conversely, if I read in the strings one line at a time, and add them to the RTB one character at a time, it's pretty much the same speed as it is when I am writing the formatted text one char at a time.

So, is there a way, to build a Rich Text string with formatting, and write it line-at-a-time to the RTB? I think if I could do that, the speed would go right up where I want it.

Bill