How to double buffer .NET controls on a form?

Question

How can I set the protected DoubleBuffered property of the controls on a form that are suffering from flicker?

Answer 1

Here's a more generic version of Dummy's solution.

We can use reflection to get at the protected DoubleBuffered property, and then it can be set to true.

Note: You should pay your developer taxes and not use double-buffering if the user is running in a terminal services session (e.g. Remote Desktop) This helper method will not turn on double buffering if the person is running in remote desktop.

public static void SetDoubleBuffered(System.Windows.Forms.Control c)
{
   //Taxes: Remote Desktop Connection and painting
   //http://blogs.msdn.com/oldnewthing/archive/2006/01/03/508694.aspx
   if (System.Windows.Forms.SystemInformation.TerminalServerSession)
      return;

   System.Reflection.PropertyInfo aProp = 
         typeof(System.Windows.Forms.Control).GetProperty(
               "DoubleBuffered", 
               System.Reflection.BindingFlags.NonPublic | 
               System.Reflection.BindingFlags.Instance);

   aProp.SetValue(c, true, null); 
}

Answer 2

Check this thread

Repeating the core of that answer, you can turn on the WS_EX_COMPOSITED style flag on the window to get both the form and all of its controls double-buffered. The style flag is available since XP. It doesn't make painting faster but the entire window is drawn in an off-screen buffer and blitted to the screen in one whack. Making it look instant to the user's eyes without visible painting artifacts. It is not entirely trouble-free, some visual styles renderers can glitch on it, particularly TabControl when its has too many tabs. YMMV.

Paste this code into your form class:

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

The big difference between this technique and Winform's double-buffering support is that Winform's version only works on one control at at time. You will still see each individual control paint itself. Which can look like a flicker effect as well, particularly if the unpainted control rectangle contrasts badly with the window's background.

Answer 3

You can also inherit the controls into your own classes, and set the property in there. This method is also nice if you tend to be doing a lot of set up that is the same on all of the controls.

Answer 4

public void EnableDoubleBuffering()
{
   this.SetStyle(ControlStyles.DoubleBuffer | 
      ControlStyles.UserPaint | 
      ControlStyles.AllPaintingInWmPaint,
      true);
   this.UpdateStyles();
}

Answer 5

I have found that simply setting the DoubleBuffered setting on the form automatically sets all the properties listed here.

However; I have found the double buffering provided by winforms to be less than great. This little gem of a code snippet really makes a difference, seriously try it. I spent a long time looking for a solution that worked and finally found that :-)

Answer 6

vb.net version of this fine solution....:

Protected Overrides ReadOnly Property CreateParams() As CreateParams
    Get
        Dim cp As CreateParams = MyBase.CreateParams
        cp.ExStyle = cp.ExStyle Or &H2000000
        Return cp
    End Get
End Property