WNetGetLastErrorW function (winnetwk.h)

Article
02/22/2024

The WNetGetLastError function retrieves the most recent extended error code set by a WNet function. The network provider reported this error code; it will not generally be one of the errors included in the SDK header file WinError.h.

Syntax

DWORD WNetGetLastErrorW(
  [out] LPDWORD lpError,
  [out] LPWSTR  lpErrorBuf,
  [in]  DWORD   nErrorBufSize,
  [out] LPWSTR  lpNameBuf,
  [in]  DWORD   nNameBufSize
);

Parameters

[out] lpError

Pointer to a variable that receives the error code reported by the network provider. The error code is specific to the network provider.

[out] lpErrorBuf

Pointer to the buffer that receives the null-terminated string describing the error.

[in] nErrorBufSize

Size of the buffer pointed to by the lpErrorBuf parameter, in characters. If the buffer is too small for the error string, the string is truncated but still null-terminated. A buffer of at least 256 characters is recommended.

[out] lpNameBuf

Pointer to the buffer that receives the null-terminated string identifying the network provider that raised the error.

[in] nNameBufSize

Size of the buffer pointed to by the lpNameBuf parameter, in characters. If the buffer is too small for the error string, the string is truncated but still null-terminated.

Return value

If the function succeeds, and it obtains the last error that the network provider reported, the return value is NO_ERROR.

If the caller supplies an invalid buffer, the return value is ERROR_INVALID_ADDRESS.

Remarks

The WNetGetLastError function retrieves errors that are specific to a network provider. You can call WNetGetLastError when a WNet function returns ERROR_EXTENDED_ERROR.

Like the GetLastError function, WNetGetLastError returns extended error information, which is maintained on a per-thread basis. Unlike GetLastError, the WNetGetLastError function can return a string for reporting errors that are not described by any existing error code in WinError.h.

For more information about using an application-defined error handler that calls the WNetGetLastError function, see Retrieving Network Errors.

Note

The winnetwk.h header defines WNetGetLastError as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	winnetwk.h
Library	Mpr.lib
DLL	Mpr.dll