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How to know LockWindowUpdate state for a specified control

Hello,
I'm using Windows.LockWindowUpdate in order to optimize control's drawing while moving and resizing.
Something like this:

LockWindowUpdate(MyPanel.Handle);
//some code here
//...
//...
LockWindowUpdate(0);

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Sometimes I need to know if LockWindowUpdate is enabled or disabled for a specified control.
Something like "IsWindowUpdateLocked()".
How can this be done? (If it can be done..)
Thanks for your willingness.

akb

The only way I can think to do it is to define a Boolean flag to go with each control you want to know the status of and set it to true or false as you set lockwindowupdate on or off.

Sinisa Vuk

According to this: http://msdn.microsoft.com/en-us/library/windows/desktop/dd145034%28v=vs.85%29.aspx

A locked window cannot be moved

Try to use Panel.DoubleBuffered:=True or Form.DoubleBuffered:=True.

ExDev001

ASKER

Isn't there another way?

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Sinisa Vuk

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ExDev001

ASKER

Hello, your informations helped me in writing IsWindowUpdateLocked function.

function IsWindowUpdateLocked() : boolean;
begin
Result := not LockWindowUpdate(Application.Handle);
if(not Result)
then LockWindowUpdate(0);
end;

Consider that LockWindowUpdate fails if another window is update-locked.
Furthermore, LockWindowUpdate doesn't causes auto-update.