double buffering a windows form

[Alex Glass]

I have read plenty about applying double buffering for animation and self
drawn forms. Is there a way to apply it to a form with many standard
controls on it (textboxes, labels etc) ?? I have tried using
myForm.SetStyle s(ControlStyles .DoubleBuffer, True) however it has made no
impact on the drawing operation. Any clarification would be greatly
appreciated

-Alex

[Jamin Guy]

http://www.bobpowell.net/doublebuffer.htm

Double buffering will only affect the Form.OnPaint method, which you
will have to override if you use the techniques described in the link
above. The controls on your form all have their own OnPaint methods,
which have nothing to do with the form's double buffering. You would
have to implement double buffering on each individual control...

[Alex Glass]

I tried implementing double buffering on a single control without success.
Any idea what im missing here? The datagrid no longer paints at all, its
just a black box.

The form event
Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
If m_buffer Is Nothing Then
m_buffer = New Bitmap(Me.Clien tSize.Width, Me.ClientSize.H eight)
dg.Buffer = m_buffer
End If

Dim g As Graphics = Graphics.FromIm age(m_buffer)
g.Clear(SystemC olors.Control)
g.Dispose()

'Copy the back buffer to the screen

e.Graphics.Draw ImageUnscaled(m _buffer, 0, 0)
End Sub

Protected Overrides Sub OnPaintBackgrou nd(ByVal pevent As
PaintEventArgs)
'Don't allow the background to paint
End Sub

Protected Overrides Sub OnSizeChanged(B yVal e As EventArgs)
If Not (m_buffer Is Nothing) Then
m_buffer.Dispos e()
m_buffer = Nothing
End If

MyBase.OnSizeCh anged(e)
End Sub
The derived class
Public Class BufferedDataGri d
Inherits DataGrid

Private m_buffer As Bitmap

Public Property Buffer() As Bitmap
Get
Return m_buffer
End Get
Set(ByVal Value As Bitmap)
m_buffer = Value
End Set
End Property

Public Sub New()
SetStyle(Contro lStyles.AllPain tingInWmPaint Or
ControlStyles.U serPaint Or ControlStyles.D oubleBuffer, True)
End Sub

Protected Overrides Sub OnPaint(ByVal pe As
System.Windows. Forms.PaintEven tArgs)
If m_buffer Is Nothing Then Return
Dim peArgs As New PaintEventArgs( Graphics.FromIm age(m_buffer),
pe.ClipRectangl e)
MyBase.OnPaint( peArgs)
End Sub

End Class

"Jamin Guy" <ja******@gmail .com> wrote in message
news:11******** *************@g 14g2000cwa.goog legroups.com...

http://www.bobpowell.net/doublebuffer.htm

Double buffering will only affect the Form.OnPaint method, which you
will have to override if you use the techniques described in the link
above. The controls on your form all have their own OnPaint methods,
which have nothing to do with the form's double buffering. You would
have to implement double buffering on each individual control...

[Jamin Guy]

I'm not sure if you can make a custom drawn DataGrid, but here is an
example of a custom StatusBar that I double-buffered.

public class StatusBarEx : StatusBar
{
private int xBuffer = 4, yBuffer = 4;

public StatusBarEx()
{
InitializeCompo nent();

//
// TODO: Add constructor logic here
//

this.SetStyle(C ontrolStyles.Do ubleBuffer |ControlStyles. UserPaint |
ControlStyles.A llPaintingInWmP aint |
ControlStyles.R esizeRedraw, true);
}

protected override void OnPaint(PaintEv entArgs e)
{
base.OnPaint (e);
Rectangle drawingRect = new Rectangle(new Point(xBuffer, yBuffer),
new Size(this.Clien tRectangle.Widt h - xBuffer,
this.ClientRect angle.Height - yBuffer));
e.Graphics.Draw String(this.Tex t, this.Font, new
SolidBrush(Colo r.DimGray), drawingRect);
}

private void InitializeCompo nent()
{
//
// StatusBarEx
//
this.Font = new System.Drawing. Font("Arial", 9.75F,
System.Drawing. FontStyle.Bold, System.Drawing. GraphicsUnit.Po int,
((System.Byte)( 0)));

}

protected override void OnTextChanged(E ventArgs e)
{
base.OnTextChan ged (e);

this.Refresh();
}