How to avoid image Flickering in VB.NET?

[Juliano]

Hi,

 

I´m trying to draw a rectangle, for example, in a Form.

I do the following:

 

public graphic as Graphics

 

in the Form_Load I do:

 

graphic = Me.CreateGraphics

Me.SetStyle(ControlStyles.DoubleBuffer, True)

Me.SetStyle(ControlStyles.UserPaint, True)

Me.SetStyle(ControlStyles.AllPaintingInWmPaint, True)

 

in the Timer_Tick I do:

 

For i = 0 to 100

graphic.Clear(Color.White)

graphic.FillRectangle(Brushes.Blue, 0, 0, 50, 50)

Next

 

I want the rectangle to move without flickering the image, but I can´t avoid the flickering.

 

What am I doing wrong?

 

thanks,

Juliano.

[aewarnick]

You aren't overriding OnPaint and using e to paint with. You don't need CreateGraphics.

[Volte]

Also, I believe you need to set the styles in the constructor, not in the Load event.

[Hamburger1984]

you should move all your drawing-code into the OnPaint override - like aewarnick said - and use e.Graphics there... in the Timer_Tick-Event you then simply do a "Me.Invalidate()" to tell the Form to redraw... should be flicker-free now...

 

Andreas

[aewarnick]

Store your tick value and Box size Rectangle value in global variables at the top of the Form, below the Form class.

[ThePentiumGuy]

Also, I believe you need to set the styles in the constructor, not in the Load event.

 

actually, you can store the styles in the load event, (i dunno, it seems to work for me when i do that)

[aewarnick]

That makes sense...only becasue when using SetStyle you have the choice of whether you want it set or not using the bool value.

 

I am pretty sure then that you can switch DoubleBuffing on and off any time you want.