"Kristopher Wragg" <xafier@xafiers-home.com> wrote in message
news:1145459982.304438.305660@i39g2000cwa.googlegroups.com...
> Hi,
>
> I'm creating some controls that basically draw shapes with/without text
> inside/outside etc, pretty customizeable shapes including square,
> circle, star...
>
> I'm having a problem when their anchors are set so they resize with the
> parent control, they're flickering like mad and I cant seem to get them
> to double buffer and resize nicely...
>
> To get transperency to work correctly I've had to use:
>
> protected override CreateParams CreateParams
> {
> [SecurityPermission(SecurityAction.Assert, UnmanagedCode = true)]
> get
> {
> CreateParams cp = base.CreateParams;
> cp.ExStyle |= 0x00000020; //WS_EX_TRANSPARENT
> return cp;
> }
> }
>
> Inside my constructor:
>
> SetStyle(ControlStyles.AllPaintingInWmPaint, true);
> SetStyle(ControlStyles.ResizeRedraw, true);
> SetStyle(ControlStyles.UserPaint, true);
>
> I've overridden OnPaintBackground so that it doesn't call
> base.OnPaintBackground
>
> I'm also using a backbuffer image so it only blits at the end of the
> painting method, but it's still flickering like mad on resize, and the
> painting isn't that complex, especially for the circle and square
> shapes, FillRect, DrawRect, DrawString, thats about it
>
> Anyone have any tips?
>
> Most of my transperency code has come from
> http://www.bobpowell.net/transcontrols.htm and a few other sites with
> similar content, it's been a royal pain in the behind trying to get
> such a simple thing as circles and stars to be drawn nicely on top of
> forms with background images and such
>
> thanks,
> Kris Wragg
>

"Kristopher Wragg" <xafier@xafiers-home.com> wrote in message
news:1145519915.589599.135880@g10g2000cwb.googlegroups.com...
> Hi Bob,
>
> I saw that example on your site already, but I dont think it meets my
> needs as these are actually real controls with a fair bit of code
> behind them.
>
> They're not just painting shapes, they dynamically change via events
> driven from an alert server, update their colour, text, sometimes
> position... theres a fair bit of code behind them.
>
> Also they're part of a product that will allow customers to drag these
> onto a "canvas" and create dynamic views with various other components,
> which they can select these controls and change the properties as to
> how they react and change.
>
> Is there no way to double buffer a control that uses transperancy then?
> So far I've managed to stop the flickering at the expense of it not
> updating till the user stops resizing the parent by setting a flag when
> resize occurs and then not setting it to true (to paint) until
> Application.Idle event fires... but I still don't like this approach as
> it'd be nice for them to resize like everything else and not flicker!
>
> many thanks for your site btw, it's helped me a lot with dipping my
> toes into .NET coding :)
>
> Kris Wragg
>

"Kristopher Wragg" <xafier@xafiers-home.com> wrote in message
news:1145519915.589599.135880@g10g2000cwb.googlegroups.com...
> Hi Bob,
>
> I saw that example on your site already, but I dont think it meets my
> needs as these are actually real controls with a fair bit of code
> behind them.
>
> They're not just painting shapes, they dynamically change via events
> driven from an alert server, update their colour, text, sometimes
> position... theres a fair bit of code behind them.
>
> Also they're part of a product that will allow customers to drag these
> onto a "canvas" and create dynamic views with various other components,
> which they can select these controls and change the properties as to
> how they react and change.
>
> Is there no way to double buffer a control that uses transperancy then?
> So far I've managed to stop the flickering at the expense of it not
> updating till the user stops resizing the parent by setting a flag when
> resize occurs and then not setting it to true (to paint) until
> Application.Idle event fires... but I still don't like this approach as
> it'd be nice for them to resize like everything else and not flicker!
>
> many thanks for your site btw, it's helped me a lot with dipping my
> toes into .NET coding :)
>
> Kris Wragg
>