Double Buffering and MyBase.OnPaint(pe)

[DraguVaso]

Hi,

I have my custom Inherited DataGrid. I override the OnPaint-event to speed
up things and avoid flikkering using Double Buffering. To draw the normal
things of the DataGrid I have to call the MyBase.OnPain(pe). But in my
opinion it doesn't seem to be painted on the buffer. Everything works fine,
but I think it should work better if my MyBase.OnPaint also painted in my
buffer.

Am I wrong? And how should I do this? I kind of need to link the pe-argument
to my g-object?

This is the code :

Protected Overrides Sub OnPaint(ByVal pe As
System.Windows.Forms.PaintEventArgs)
'DoubleBuffer-functions********
If _backBuffer Is Nothing Then
_backBuffer = New Bitmap(Me.ClientSize.Width,
Me.ClientSize.Height)
End If

Dim g As Graphics = Graphics.FromImage(_backBuffer)
'Paint on the Graphics object here
'DoubleBuffer-functions********

MyBase.OnPaint(pe)

'I do my special stuff here with the g-object (custom cilumnheaders etc
'....


'DoubleBuffer-functions********
g.Dispose()
'Copy the back buffer to the screen
pe.Graphics.DrawImageUnscaled(_backBuffer, 0, 0)
'DoubleBuffer-functions********
End Sub

Thanks a lot in advance!

Pieter

 

[Ken Tucker [MVP]]

Hi,

Why dont you use setstyle for the control to doublebuffer.

http://msdn.microsoft.com/library/d...stemwindowsformscontrolclasssetstyletopic.asp

Ken
----------------------
Hi,

I have my custom Inherited DataGrid. I override the OnPaint-event to speed
up things and avoid flikkering using Double Buffering. To draw the normal
things of the DataGrid I have to call the MyBase.OnPain(pe). But in my
opinion it doesn't seem to be painted on the buffer. Everything works fine,
but I think it should work better if my MyBase.OnPaint also painted in my
buffer.

Am I wrong? And how should I do this? I kind of need to link the pe-argument
to my g-object?

This is the code :

Protected Overrides Sub OnPaint(ByVal pe As
System.Windows.Forms.PaintEventArgs)
'DoubleBuffer-functions********
If _backBuffer Is Nothing Then
_backBuffer = New Bitmap(Me.ClientSize.Width,
Me.ClientSize.Height)
End If

Dim g As Graphics = Graphics.FromImage(_backBuffer)
'Paint on the Graphics object here
'DoubleBuffer-functions********

MyBase.OnPaint(pe)

'I do my special stuff here with the g-object (custom cilumnheaders etc
'....


'DoubleBuffer-functions********
g.Dispose()
'Copy the back buffer to the screen
pe.Graphics.DrawImageUnscaled(_backBuffer, 0, 0)
'DoubleBuffer-functions********
End Sub

Thanks a lot in advance!

Pieter

 

[DraguVaso]

Hi,

I did that already. I based my solution to this:
www.bobpowell.net/doublebuffer.htm

although by relooking to it I think I'm having automatic and manual double
buffering together in my application, hehe

 

[Miha Markic [MVP C#]]

Please, don't cross-post in irrelevant newsgroups (ado.net????).

 

[Guest]

I'm not sure but I think one disadvantage to the method you are using with
the _BackBuffer is that you are repainting the entire control each time the
paint event is fired rather than just the invalidated rectangle...depending
on what you are painting each time, maybe you have to do this.

 

[DraguVaso]

That's indeed a good remark. Although the Paint-event repaints every time
the whole DataGrid, so I need to repaint my stuff also each time :-/ it
should be nicer indeed if I could disable some things to be repainted, but
idon't know if something like that is possible or not.

with disabling the paint of the background I guess saved alreaddy some
time...