如何获取特定RichTextBox控件可以在同一行上显示的字符串的最大长度？

Question

I'm using the regular System.Windows.Form.RichTextBox control for a WinForm application running on the .NET Framework 2.0 to show a status log. Since the Form and several other child controls, have AutoSize=True , the application does not always look the same way on different setups. I have no way to know in advance the exact size of the control and anyway I guess there are some implications related to the ratio (font appearence)/(gui dimensions) of each particular configuration.

So now let's depict the most dynamic scenario. I want to know what's the exact maximum length of the string, a given RichTextBox can show on the same line (without exceeding the border nor word wrapping) where such a RichTextBox is using a generic and known, monospaced font and size.

In case there's no any straightforward way to accomplish this result, does anyway know if I may use any kind of trick like injecting an incrementally growing test string till some weird event gets fired?

Answer 1

That's what I got till now. I used the TextRenderer class and the strategy I anticipated on my question above. Of course it makes sense only if the control uses a monospaced font. Despite it works for my problem, I'm still curious to know if anyone knows a better way to reach the same goal. So the question will still be open for a while.

int maxStringLength = GetMaxStringLengthPerLine(myRichTextBox);

int GetMaxStringLengthPerLine(RichTextBox textbox) {
   return GetMaxStringLength(textbox.Size.Width, textbox.Font);
}

int GetMaxStringLength(int width, Font font) {
   int i = 0;
   while(TextRenderer.MeasureText(new string('A',++i), font).Width<=width);
   return --i;
}