OleCreatePictureIndirect() WinAPI call problem

[Guest]

I got problems with the WinAPI call OleCreatePictureIndirect() in C#.

Has anybody ever used this function call in C#?

Thanks,

Minfu

 

[Nicholas Paldino [.NET/C# MVP]]

Minfu,

What kind of problems are you having?

 

[Guest]

The purpose of using this function is to copy the image of a form to the
system clipboard.

 

[Nicholas Paldino [.NET/C# MVP]]

Yes, but you say you are having problems. What are the problems you are
having?

Also, have you checked http://www.pinvoke.net for the definition of the
function in .NET?

 

[Guest]

This problem is the fouth Out paramter IPicture. I defined a
System.Drawing.Iamge variable and passed it as Out. An unhandled exception
occurs every time when I call this function. I searched
http://www.pinvoke.net, but there is NO any info for this API.

 

[Nicholas Paldino [.NET/C# MVP]]

Minfu,

Just curious, why do you want to call this API? You can take the handle
of an Icon, or bitmap, and pass it to the static FromHbitmap method on the
Image class, or to the static FromHandle method on the Icon class.

Or is there another reason you want to use this API?

 

[Willy Denoyette [MVP]]

This problem is the fouth Out paramter IPicture. I defined a
System.Drawing.Iamge variable and passed it as Out. An unhandled exception
occurs every time when I call this function. I searched
http://www.pinvoke.net, but there is NO any info for this API.

"Out" means that the callee returns a value, you should not pass anything
but an IntPtr, the received value is an Interface pointer for the COM
Interface requested (in second arg.), this interface can be used to access
the COM IPicture object that corresponds to the bitmap passed as first
argument.
But, I have to ask why you need to call this function, you are trying to
mix System.Drawing.Image (GDI+ ) with COM based (OLE) GDI access, this is
something you try to avoid by all means.

Willy.