Get rid of label margins

Tony Pottier

I'm using several labels located next to each other thanks to left docking and the autosize property. The thing is, even if you set margin/padding to 0, there's still a margin: Picture explaining the problem: http://uppix.net/5/1/2/69b945ab92a5598fb93aca1d50be6.jpg[^] How to get rid of this? I'm using labels because each label can have a different color/font/ The RTF box is a no go as it doesn't have any autosize property and it doesnt behave like a label (you can select the text). "RTF label" control on this website doesnt have the autosize property and you can still select the text...

Dave Kreskowiak

You can't get rid of it. If this is a problem, why even use a Label? Why not just render the text yourself with DrawString? You'd probably end up doing the same thing if you made your own Label control and supplied your own drawing code anyway.

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Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
2006, 2007, 2008

realJSOP

You could write your own label class that simply overrides the base paint method.

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

Tony Pottier

I can't use DrawString because I need to know the exact length of the text: that's why the autosize property is so convenient. I just set the texts of the labels and add the width properties to know the final length of all the labels. If I'm using DrawString or something that overrides the WM_PAINT of the label, how do I know the length in pixels of the text?

Dave Kreskowiak

Tony_P wrote:

I can't use DrawString because I need to know the exact length of the text

That's what MeasureString is for.

A guide to posting questions on CodeProject[^]
Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
2006, 2007, 2008

Tony Pottier

Alright I've just found this in the meantime. Thank you for your time!

Tony Pottier

this is what I came up with:

public class EnhancedLabel : Label
{
protected override void OnPaint(PaintEventArgs e)
{
Graphics g = e.Graphics;
Brush fore = new SolidBrush(this.ForeColor);
Brush back = new SolidBrush(this.BackColor);

        SizeF s = g.MeasureString(this.Text, this.Font);
        this.Width = (int)s.Width;
        this.Height = (int)s.Height;

        g.FillRectangle(back, this.Left, this.Top, this.Width, this.Height);
        g.DrawString(this.Text, this.Font, fore, this.Location);
    }
}

Tony Pottier

And a version 2.0, much better ;o

protected override void OnPaint(PaintEventArgs e)
{
Graphics g = e.Graphics;
Brush fore = new SolidBrush(this.ForeColor);
Brush back = new SolidBrush(this.BackColor);

        g.FillRectangle(back, this.Location.X, this.Location.Y, this.Width, this.Height);
        g.DrawString(this.Text, this.Font, fore, Point.Empty);
    }

    protected override void OnTextChanged(EventArgs e)
    {
        Graphics g = System.Drawing.Graphics.FromHwnd(this.Handle);
        SizeF s = g.MeasureString(this.Text, this.Font);
        this.Width = (int)s.Width;
        this.Height = (int)s.Height;

        base.OnTextChanged(e);
    }

DaveyM69

Just a couple of points - You should dispose of your brushes, or better still put them in using blocks.

using (Brush back = new SolidBrush(ForeColor))
{
e.Graphics.FillRectangle(back, Location.X, Location.Y, Width, Height);
}
using (Brush fore = new SolidBrush(BackColor))
{
e.Graphics.DrawString(Text, Font, fore, Point.Empty);
}

You can use the Size struct's static Round method to convert the SizeF

Size = Size.Round(s);

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)

Tony Pottier

Right, thank you for the tips. I used the brushes without even checking if it was a disposable object. Shame on me.

Luc Pattyn

Hi, the most expensive one, the one you really should dispose of, is the result of Graphics.FromHwnd() for the brushes, you might consider keeping them in a class member, rather than creating and disposing them all the time. creating a Graphics, as you do, is something I avoid even at modest cost; so I am not in favor of your 2.0 solution; instead I would do everything in OnPaint, possibly do MeasureString inside a test on text changed. :)

Luc Pattyn [Forum Guidelines] [My Articles]

Fixturized forever. :confused:

Tony Pottier

Well the problem is that I need the width/height of the label without painting it, so I can't do everything in the paint event. The best way is probably to store the brushes, for sure. Can I store the Graphics.FromHwnd() the same way or can the value of Graphics.FromHwnd() change?

Luc Pattyn

Tony_P wrote:

I need the width/height of the label without painting it

Huh? if you need it inside OnPaint only, then do the MeasureString in OnPaint just before you use DrawString. if you need its result outside OnPaint, I would try and execute OnPaint once before you need the sizes. Keeping a Graphics does not feel right; for one it is an expensive object, and it contains many things that may be different each time you get a graphics; e.g. every time you move ab object over a Form, the Form may get Paint events with varying clip regions in the Graphics object. Also the user might change the resolution of the screen, and whatever more. :)

Luc Pattyn [Forum Guidelines] [My Articles]

Fixturized forever. :confused:

realJSOP

Why don't you just write a function that does something like this:

class BlahBlah
{
SizeF m_textSize;

public SizeF MeasureText(string text)
{
    (using Graphics graphics = Graphics.FromHwnd(this))
    {
        m\_textSize = graphics.MeasureString(text, someFont);
    }
    return m\_textSize;
}

}

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

Luc Pattyn

I will do such things only if I see no reasonable alternative; I try and avoid creating a new Graphics as much as I can. In OnPaint the Graphics is for free, so why not take advantage of that one? In the few 100K lines of C# code I have at hand, I found only two instances of Graphics.FromHwnd; I do use Graphics.FromImage of course when drawing onto a Bitmap, there simply is no alternative there. :)

Luc Pattyn [Forum Guidelines] [My Articles]

Fixturized forever. :confused: