Memory problem with drawing 2

[Disferente]

I have made a program that is drawing something every second and I noticed that everytime it draws something the memory usage of the program increases, is there anyway of preventing this?

I use Me.CreateGraphics.FillRectangle with a solidbrush that I dispose of after every time.

 

[Qik3Coder]

You may want to attempt to call the Garbage collector manually with a gc.collect. be sure and "Nothing" any of the external references in the object.

If [blue]you have problems[/blue], I want [green]source code[/green] AND [green]error messages[/green], none of this [red]"there was an error crap"[/red]

 

[RiverGuy]

Also, are you sure that the memory isn't being released? Are you letting the program continue to run, or exiting right away?

As an aside, the only time I've had issues like this that I could not resolve was when I was evaluating VB Express 2008. I was never sure what it was and the same code performed much better in VB Express 2005. I haven't had any issues with Visual Studio 2008 either.

 

[Disferente]

In the beginning it looked like gc.collect were working, the memory usage was going up and down a bit, but when I let it run for an hour and then looked it was up at 98mb (from 21 when it started) of memory usage and increasing by 500kb/s.
When I try to access the program after that happens it throws an exception

An unhandled exception of type 'System.OutOfMemoryException' occurred in system.drawing.dll
Additional information: Out of memory.

> system.drawing.dll!System.Drawing.Graphics::FromHdcInternal(__int32 hdc = 0) + 0x38 bytes

Any idea of what is going on?

 

[DaveInIowa]

You say you're disposing of the brush every time but could the Graphics object need to be disposed of also?

Dim g As Graphics = Me.CreateGraphics

g.FillRectangle ...

g.Dispose()

 

[RiverGuy]

Good call Dave. I'd also suggest not using Me.CreateGraphics. You can get access to your form's graphics objects in the OnPaint event.

 

[Disferente]

RiverGuy: Exactly how do you mean? Not using Me.CreateGraphics?

 

[RiverGuy]

If you're in your Paint event, you can use e.graphics

 

[Disferente]

So I put the code to draw in the paint event and use e.graphics directly or by Dim g As Graphics = e.CreateGraphics and then call the paint event by me.refresh()?

 

[DaveInIowa]

You would use e.Graphics directly but instead of calling Me.Refresh, you should use the Invalidate method of the control housing your drawing. Call the Invalidate method in place of where you were originally doing your drawing. You could use Me.Invalidate but that's probably overkill on the region that you need to repaint.

 

[Disferente]

I am using the entire form to paint on, I don't have any visible controls on it.

 

[Disferente]

It seems like it works fine with those changes, I'll leave it on for a couple more hours and I'll see then.

 

[Disferente]

Seems to be working just fine now, had some problem so I could not access the computer for the weekend and when I came back it was still running. Thank you all for your help