SetLastErrorEx

The SetLastErrorEx function sets the last-error code. In Windows 95 and in Windows NT, this function is identical to the SetLastError function. The second parameter is not implemented.

VOID SetLastErrorEx(

DWORD dwErrCode, // per-thread error code
DWORD dwType // error type
);  

Parameters

dwErrCode

Specifies the last-error code for the thread.

dwType

Specifies the error type. If this process is being controlled by a debugging process, the debugger may take action based on the error type. This parameter can have one of the following values:

Value Meaning
SLE_ERROR Invalid data was passed to the function, and complete failure has occurred.
SLE_MINORERROR Invalid data was passed to the function, but the function has recovered.
SLE_WARNING Potentially invalid data was passed to the function, but the function has recovered.
0 The last-error code is set without reporting anything to the debugger. Specifying this value is equivalent to using the SetLastError function.

Remarks

Error codes are 32-bit values (bit 31 is the most significant bit). Bit 29 is reserved for application-defined error codes; no Win32 API error code has this bit set. If you are defining an error code for your application, set this bit to indicate that the error code has been defined by the application and to ensure that your error code does not conflict with any system-defined error codes.

This function is intended primarily for dynamic-link libraries (DLLs). Calling this function after an error occurs allows the DLL to emulate the behavior of the Win32 API.

Most Win32 functions call SetLastError when they fail. Function failure is typically indicated by a return value error code such as FALSE, NULL, 0xFFFFFFFF, or -1. Some functions call SetLastError under conditions of success; those cases are noted in each function's reference page.

Applications can retrieve the value saved by this function by using the GetLastError function.

The last-error code is kept in thread local storage so that multiple threads do not overwrite each other's values.

See Also

GetLastError, SetLastError