Drawing onto various controls..

[wyrd]

Theres an app Im programming that draws images on specific parts of the form. Im using labels to represent the areas and just drawing on to those by doing;

Graphics g = label.CreateGraphics();
g.DrawImage(...);

However whenever I minimize and then unminimize the form it leaves the labels blank as if clearing them. Or a menu simply drops down in front of a label then goes away, it leaves a cleared area of where that menu was.

Should I not be using labels or am I missing something? Im pretty sure I put code to refresh the label images in the Form_Paint method. *ponders* Maybe I should be putting it into the Label_Paint method..

 

[Hamburger1984]

youre right. put each controls drawing code into their Paintevent handler - because the form doesnt know when a portion of a control is redrawn....

 

[wyrd]

I actually tried that last night after posting. It doesnt seem to work. Any other ideas?

 

[Hamburger1984]

could you upload/e-mail the code? Ill try to fix and comment it for you


Andreas

 

[Oriolesboy]

If you are working with a label, you can have your own class extend label and then just override the OnPaint method.

This is what I did in a certain situation.

Example, i used a label as a canvas (like in Java) just something i can draw in.

Then i created methods that do things, like maybe draw a circle:

/****************BEGIN CODE*****************/
//note: on is a variable which represents whether or not to draw
//a circle (which is a property value that can be set true/false)

private void PaintCircle(Graphics g)
{
if (this.on == true)
{
g.FillEllipse(Brushes.Aquamarine, new Rectangle(0,0,this.Width, this.Height));
}
else
{
g.FillEllipse(new SolidBrush(this.BackColor), new Rectangle(0,0,this.Width, this.Height));
}
}
/*********************END CODE****************/

now I simply override the onpaint method:

/**************BEGIN CODE*****************/
protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
Graphics g = e.Graphics;
this.PaintCircle(g);
}
/***************end code*******************/

I understand this may not help you in your situation, but I hope it does.

 

[wyrd]

Oriolesboy:
Ill toy around and see what I come up with. BTW you can use cs tags to place c# code; <cs>code</cs> (replace < > with [ ])