Thread: Problem with SetWindowLongPtr

Hi!

I've got a problem with using SetWindowLongPtr. I tried using this code, but it doesn't seem to work:

Code:

LONG toolWindowExStyle = WS_EX_TOOLWINDOW;
ShowWindow(hwnd, SW_HIDE);

SetWindowLongPtr(hwnd, GWL_EXSTYLE, (LONG_PTR) &toolWindowExStyle);

ShowWindow(hwnd, SW_SHOW);

However, this works perfectly:

Code:

ShowWindow(hwnd, SW_HIDE);

SetWindowLong(hwnd, GWL_EXSTYLE, WS_EX_TOOLWINDOW);

ShowWindow(hwnd, SW_SHOW);

I'd really appreciate it if someone could point out the mistake.

Thanks!

PS: BTW, I'm using Windows XP, Microsoft Visual Studio 2005 and have used "#undef UNICODE" and "#undef _UNICODE" on top of the source code.

Hi!

I just figured out from looking at source code on the 'net that I can use:

ShowWindow(hwnd, SW_HIDE);
SetWindowLongPtr(hwnd, GWL_EXSTYLE, WS_EX_TOOLWINDOW);
ShowWindow(hwnd, SW_SHOW);

However, isn't WS_EX_TOOLWINDOW supposed to be a LONG rather than a pointer to a LONG? I mean I thought the function expected a pointer to a long so I initially tried giving it a pointer to a long.

-Confused

The function takes a LONG, not a pointer to LONG.

No it doesnt. If you look in the intsafe.h or baseTsd.h header file, you will see

Code:

typedef [public]          __int3264 LONG_PTR;

The fact that the type name has PTR stuck at the end means absolutely nothing. The LONG_PTR variable is used whenever a pointer is casted to a signed long.