DoubleBuffer problem ..

Sharpoverride

whenever i use setstyle( ... ) ; and in my paint function i do something like void paintMethod( .., .. ) { using( Graphics g = e.Graphics ) { g.doesSomeDrawing(); } } the ... statements replace the actual code wich is corect i am getting an error message saying "Additional information: Invalid parameter used." and if i don't use the using statement everything works fine .. no error message !:omg: Lazar Mihai Elev clasa XI C Grup Scolar Sanitar

Gary Thom

I suspect it is the using you are copying an existing Graphics object, not assigning a new one. Gary In Scotland, there is no such thing as bad weather - only the wrong clothes. - Billy Connolly

Dave Kreskowiak

You can either not use the using statement, safely, or you can try something like this:

Graphics g = e.Graphics;
using ( g )
{
    g.doesSomeDrawing();
}

RageInTheMachine9532 "...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Skynyrd

The answer is simple. The using statement resolves to the following code: try { g.doesSomeDrawing(); } finally { g.Dispose(); } U are disposing a graphics object that u dont "own" (e.graphics). On a general basis you should only dispose graphic objects that you explicitly create through the Control's CreateGraphics() method or through a New Graphics() statement;

Heath Stewart

The actual exception is because the caller of OnPaint (most often WndProc) is trying to dispose the Graphics object and it's already been disposed. He should not be using using at all. This posting is provided "AS IS" with no warranties, and confers no rights. Software Design Engineer Developer Division Sustained Engineering Microsoft [My Articles] [My Blog]

Dave Kreskowiak

I thought it might be something along those lines, wasn't sure though. Too drugged up to think about it and no VS.NET at work to test it with. 8( Let me tell you, life sucks without a compiler at fingertips! RageInTheMachine9532 "...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Heath Stewart

I didn't have a compiler. :) Basically, if you didn't alloc it then you don't free it. In native APIs this isn't always the case, though, since some APIs alloc memory and expect the caller to free it. Such APIs should always document such a requirement. This posting is provided "AS IS" with no warranties, and confers no rights. Software Design Engineer Developer Division Sustained Engineering Microsoft [My Articles] [My Blog]

Dave Kreskowiak

Heath Stewart wrote: Basically, if you didn't alloc it then you don't free it. In native APIs this isn't always the case, I've run into that many a time. :-D I just wanted to try it before I stuck my foot in my mouth. RageInTheMachine9532 "...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Sharpoverride

Thanks.. I get it now.. U've all been of great help Lazar Mihai The road to becoming a good programmer is paved with bad scripts !