What's a device context?

[TpOreilly]

Could you tell me in human terms what we are talking about when we refer to a device context/display context.

Thanks

[Paul McKenzie]

Could you tell me in human terms what we are talking about when we refer to a device context/display context.

Thanks

When you display output, it has to display on something -- that "something" is the device context. It could be a particular window, a printer, etc.

Regards,

Paul McKenzie

[TpOreilly]

HDC handleDeviceContext;
PAINTSTRUCT PaintSt;
handleDeviceContext= BeginPaint(hWnd, &PaintSt);

"HDC handleDeviceContext;" - Here we are creating a variable which will be a handle to a device context.

"PAINTSTRUCT PaintSt;" - Not 100% sure what is stored in here?

"handleDeviceContext= BeginPaint(hWnd, &PaintSt);" - This is where the device context actually comes from. This function returns a device context.

So a device context is just a virtual area which we use to paint graphical output.

Am i right in the above statements?

Ive got the feeling im not quite right here, but thats why you nice people are willing to clear things up, i hope

[Paul McKenzie]

"PAINTSTRUCT PaintSt;" - Not 100% sure what is stored in here?

Just look at MSDN as to what BeginPaint() does.

So a device context is just a virtual area which we use to paint graphical output.

Yes. In addition, see functions such as GetDeviceCaps() as an example. It takes a device context, and returns, given what you're asking for, information on that device context.

http://msdn.microsoft.com/en-us/libr...=vs.85%29.aspx

Regards,

Paul McKenzie

[Skizmo]

"PAINTSTRUCT PaintSt;" - Not 100% sure what is stored in here?

Some years ago 2 guys created a revolution on the internet. It has to do with searching... they called themselves google. Learn to use it.

PAINTSTRUCT

[cilu]

One additional link http://msdn.microsoft.com/en-us/library/azz5wt61.aspx.

[TpOreilly]

Seeing as we dont modify the attributes of the PAINTSTRUCT variable, the must be default values. By default does this make the device context area the size of the whole client area?

(This question is targeted at the rcPaint attribute of the structure)