Determine Label Size based upon amount of text and font size in Winforms/C#

Mart237n_Marconcini_2684 0
Viewed 55433

I'd like to know if there's a better approach to this problem. I want to resize a label (vertically) to accomodate certain amount of text. My label has a fixed width (about 60 chars wide before it must wrap), about 495 pixels. The font is also a fixed size (12points afaik), but the text is not.

What I want to do is increase the Label Height when there's a "NewLine" or the text must wrap; the idea is that the text is fully visible in the label. The AutoSize doesn't work because it will grow in width, not in height.

Of course I could count the number of NewLines and add: Newlines * LineHeight, and then -given that I manage to put 60 chars per line, just divide the number of chars and add as many LineHeight pixels as needed.

I was wondering if there was a more professional way to do it. Is my approach too "lame" ?

Thanks in advance.

winforms .net c#
12 Answers

How about Graphics.MeasureString, with the overload that accepts a string, the font, and the max width? This returns a SizeF, so you can round round-off the Height.

        using(Graphics g = CreateGraphics()) {
            SizeF size = g.MeasureString(text, lbl.Font, 495);
            lbl.Height = (int) Math.Ceiling(size.Height);
            lbl.Text = text;
        }
Marc_Gravell_233540

System.Drawing.Graphics has a MeasureString method that you can use for this purpose. Use the overload that takes a string, a font, and an int "width" parameter; this last parameter specifies the maximum width allowed for the string - use the set width of your label for this parameter.

MeasureString returns a SizeF object. Use the Height property of this returned object to set the height of your label.

Note: to get a Graphics object for this purpose, you can call this.CreateGraphics.

MusiGenesis_146060

Graphics.MeasureString() will probably help you.

This is also one of the only usecases for using the Control.CreateGraphics() call!

Quarrelsome_11430

I would like to propose an alternative since it's a label we are talking about and not just text rendering: GetPreferredSize. I tried Mark's answer and the problem is that it almost works: the label has some "padding" around the text and this needs to be taken into account in the width value of MeasureString. I couldn't find any apparent way to get this padding. While digging, I found this answer where the poster suggests to set the FlatStyle to System. That works, but unfortunately breaks the TextAlign which I wanted it to be MiddleLeft.

I poked into the Label code and I found out the GetPreferredSize which takes into account all the weird settings (FlatStyle, UseCompatibleTextRendering etc) and can give you the correct result for each case. So instead of g.MeasureString(text, lbl.Font, 495); you can do instead

lbl.GetPreferredSize(new Size(495, 0));

or even like this since the label size is already known:

lbl.GetPreferredSize(new Size(lbl.Width, 0));

In case you are wondering, 0 and 1 will be treated as int.MaxValue.

I don't know when GetPreferredSize was introduced, so back in 2008 when Mark wrote his answer, the above might not have been relevant. But if you still need something similar in 2021, GetPreferredSize might be a tiny bit handier -which returns a Size and not a SizeF.

user_13033230

Well the 60 chars might be valid for your test text, but not all characters have the same width. For instance, compare
llllllllllllllllllllllllllllllllllllllllllllllllllllllllllll
and
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww

They both have 60 characters, and yet have vastly differing widths.

user_475270

Is there any downside to using the TextRenderer class to measure the string (like in Marc's response) instead of going through the work to create a Graphics object, etc?

jean_657120

Although, its an old thread, thought it might help new visitors.

In C#, you could use control.width

user_109736300
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