asked on

HANDLE to DWORD

I have a function that needs a DWORD as one of the parameters but I currently have that value in a HANDLE. When I try to cast a HANDLE as a DWORD it says it's getting truncated and I don't get the desired results. Both are unsigned 32-int so I thought that would have been possible.

Any ideas?

Jaime Olivares

That's very strange, effectively a handler is a 32 bit value (many times a masked pointer), so this wouldn't cause a warning

HANDLE someHandle = ....... etc.
DWORD parameter = (DWORD)someHandle;

Crestline

ASKER

This is the warning i get...

warning C4311: 'type cast' : pointer truncation from 'HANDLE' to 'DWORD'

Crestline

ASKER

This is the chunk of code... Trying to get the Process Handle (not Process ID) of an application.

DWORD pid;
HWND findWindow = FindWindow("WindowsForms10.Window.8.app4", NULL);
GetWindowThreadProcessId(findWindow, &pid);
HANDLE ph = OpenProcess(PROCESS_ALL_ACCESS, false, pid);
DWORD theDword = (DWORD)ph;

Axter

Hi Crestline,
Can you post the code to include variable declarations?

Jaime Olivares

maybe you can make a test.
try to create a MessageBox with sizeof() DWORD and HANDLE

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guitaristx

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wayside

HANDLE is defined as

typedef void *HANDLE;

This would be 64 bits on a 64-bit OS; casting this to a 32 bit DWORD would generate this error.

guitaristx is spot-on.

Crestline

ASKER

I turned off 'Detect 64-bit portability issues' and I no longer get the warning. Thanks quitaristx.

Wayside, thanks for the info. I learn something new every day!