- 1 year ago
GetModuleHandleW / A - not working. Returning null every call excluding empty string
If the GetModuleHandleW
or GetModuleHandleA
function is consistently returning NULL
(or nullptr
) for every call except an empty string, there could be several potential reasons for this behavior. Here are some possible causes and troubleshooting steps:
Check the Module Name: Ensure that the module name you pass as the parameter to
GetModuleHandleW
orGetModuleHandleA
is correct. The module name should match the actual module or DLL file name you want to retrieve the handle for.Verify the Module is Loaded:
GetModuleHandleW
andGetModuleHandleA
only retrieve handles for modules that are already loaded in the process. Make sure the module you are querying is actually loaded before calling these functions. You can use theEnumProcessModules
function in combination withGetModuleFileNameEx
to enumerate the loaded modules and check their names.Consider 32-bit and 64-bit Processes: Ensure that you are using the correct variant of the function (
GetModuleHandleW
orGetModuleHandleA
) based on the type of the process you are running (32-bit or 64-bit). Mixing up the ANSI and Unicode variants can lead to unexpected results.Check Calling Convention and Character Encoding: Make sure the calling convention and character encoding used in your code match the function declaration. For example, if you are using
GetModuleHandleW
, ensure that you are using the wide character variant and passing wide strings.Permissions and Access Rights: Ensure that the user account under which the code is running has sufficient permissions and access rights to query module handles. Some modules may be protected or restricted, preventing access to their handles.
Error Handling: Check for error conditions by using
GetLastError
immediately after the function call. It can provide more information about the reason for theNULL
return value. Look up the corresponding error code using theFormatMessage
function to get a descriptive error message.
By thoroughly examining these potential causes and applying the corresponding troubleshooting steps, you should be able to determine why GetModuleHandleW
or GetModuleHandleA
is returning NULL
in your specific scenario.