Winforms Double Buffering

c# winforms doublebuffered
Xenoprimate picture Xenoprimate · Sep 15, 2010 · Viewed 19.4k times · Source

I added this to my form's constructor code:

this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.DoubleBuffer, true);

But it still shows ugly artifacts when it loads the controls, whenever they change (the form and its components change (need updating) often).

What do I need to do differently?

Answer

Hans Passant picture Hans Passant · Sep 15, 2010

This only has an effect on the form itself, not the child controls. If you have a lot of them then the time they need to take turns painting themselves becomes noticeable, it leaves a rectangular hole where the control goes that doesn't get filled up until the child control gets it turn.

What you'd need to combat this is double-buffering the entire form and the controls. That's an option available since Windows XP which made the WS_EX_COMPOSITED style flag available. Paste this into your form to turn it on:

protected override CreateParams CreateParams {
  get {
    CreateParams cp = base.CreateParams;
    cp.ExStyle |= 0x02000000;  // Turn on WS_EX_COMPOSITED
    return cp;
  }
}

It doesn't speed up the painting at all, but the form snaps onto the screen after a delay. Eliminating the visible paint artifacts. Really fixing the delay requires not using controls. Which you'd do by using the OnPaint method to draw the 'controls' and making the OnMouseClick event smart about what 'control' got clicked by the user.

Related questions

How do I double buffer a Panel?

I have a panel that has a roulette wheel on it, and I need to double buffer the panel, so that it stops flickering. Can anyone help me out? EDIT: Yes, I have tried that. panel1.doublebuffered does not exist, …

Read More
Winforms: SuspendLayout/ResumeLayout is not enough?

I have a library of a few "custom controls". Essentially we have our own buttons, rounder corner panels, and a few groupboxes with some custom paint. Despite the "math" in the OnPaint methods, the controls are pretty standard. Most of …

Read More
How do I enable double-buffering of a control using C# (Windows forms)?

How do I enable double-buffering of a control using C# (Windows forms)? I have a panel control which I am drawing stuff into and also an owner-drawn tab control. Both suffer from flicker, so how can I enable double-buffering?

Read More