GetModuleHandle
The GetModuleHandle
function returns a module handle for the specified module if the file has been
mapped into the address space of the calling process.
HMODULE GetModuleHandle(
LPCTSTR lpModuleName |
// address of
module name to return handle for |
); |
|
Parameters
lpModuleName
Points to a
null-terminated string that names a Win32 module (either a .DLL or .EXE file).
If the filename extension is omitted, the default library extension .DLL is
appended. The filename string can include a trailing point character (.) to indicate
that the module name has no extension. The string does not have to specify a
path. The name is compared (case independently) to the names of modules
currently mapped into the address space of the calling process.
If this
parameter is NULL, GetModuleHandle returns a handle of the file used to
create the calling process.
Return Values
If the
function succeeds, the return value is a handle to the specified module.
If the
function fails, the return value is NULL. To get extended error information, call
GetLastError
Remarks
The returned
handle is not global, inheritable, or duplicative, and it cannot be used by
another process.
The handles
returned by GetModuleHandle and LoadLibrary can be used in the same
functions for example, GetProcAddress
Note that the
reference count is used in FreeLibrary to determine whether to unmap the
function from the address space of the process. For this reason, use care when
using a handle returned by GetModuleHandle in a call to FreeLibrary
because doing so can cause a dynamic-link library (DLL) module to be unmapped
prematurely.
This function
must also be used carefully in a multithreaded application. There is no
guarantee that the module handle remains valid between the time this function
returns the handle and the time it is used by another function. For example, a
thread might retrieve a module handle by calling GetModuleHandle. Before
the thread uses the handle in another function, a second thread could free the
module and the system could load another module, giving it the same handle as
the module that was recently freed. The first thread would then be left with a
module handle that refers to a module different than the one intended.
See Also