As always, only do SetLastError=true if you actually intend to call GetLastError.

As always, only do SetLastError=true if you actually intend to call GetLastError.

As always, only do SetLastError=true if you actually intend to call GetLastError (This includes throwing a Win32Exception if the call fails)

    // If you did not succeed, GetLastError may give more information

• Do NOT use GetLastError, use Marshal.GetLastWin32Error

• Do NOT use GetLastError, use Marshal.GetLastWin32Error

If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError.

                    // check GetLastError value (MUST use this call. See MSDN)

    private static extern uint GetLastError();*/

   Private Declare Function GetLastError Lib "kernel32" Alias "GetLastError" () As Integer

       MsgBox(GetLastError())

       MsgBox(GetLastError())

       MsgBox(GetLastError())

       MsgBox(GetLastError())

static extern uint GetLastError();

// GetLastError is save!

Tested extensively here http://stackoverflow.com/questions/17918266/winapi-getlasterror-vs-marshal-getlastwin32error

// You should never PInvoke to GetLastError.  Call Marshal.GetLastWin32Error instead!

' You should never PInvoke to GetLastError.  Call Marshal.GetLastWin32Error instead!

Calling GetLastError directly via PInvoke is not guaranteed to work due to the CLR's internal interaction with the operating system. Instead, call Marshal.GetLastWin32Error.

/// If the function fails, the return value is TIME_ZONE_ID_INVALID. To get extended error information, call GetLastError.

/// If the function fails, the return value is zero. To get extended error information, call GetLastError.

If you forget to set the OSVersionInfoSize field of the OSVERSIONINFO struct, the function will return false. GetLastError() will return:

If you forget to set the OSVersionInfoSize field of the OSVERSIONINFO struct, the function will return false. GetLastError() will return:

Return Value - If the function succeeds, the return value is nonzero. If the function fails, the return value is zero. To get extended error information, call GetLastError.

The SetLastError flag needs to be set to true in order to retain information that would be obtained from GetLastError in the event of an error being returned.

                else if(GetLastError() == ERROR_INSUFFICIENT_BUFFER)

                    Marshal.ThrowExceptionForHR(GetLastError());

Call SetLastError(0) at the beginning of your function if you'll use GetLastError.

        /// If the function fails, the return value is TIME_ZONE_ID_INVALID. To get extended error information, call GetLastError.

        /// If the function fails, the return value is zero. To get extended error information, call GetLastError.

static extern uint GetLastError();

           throw new Win32Exception((int)GetLastError());

           throw new Win32Exception((int)GetLastError());

public static extern int CeGetLastError();

function info on msdn at http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wceactsy/html/cerefCeGetLastErrorRAPI.asp

Returns 0 for failure. Use CeGetLastError() and CeRapiGetError() to see errors on failure.

If the function cannot find an account name for the SID, the LookupAccountSid function fails and GetLastError returns ERROR_NONE_MAPPED. This can occur if a network time-out prevents the function from finding the name. It also occurs for SIDs that have no corresponding account name, such as a logon SID that identifies a logon session.

    int error = GetLastError();

        aWinErrorCode = (uint)GetLastError();

public static void SetFileOrFolderOwner(String objectName) //Note this is very basic and is silent on fail as I havent checked GetlastError and thrown an exception etc

/// <returns>Opposite of boolean.  Zero means success, non-zero means fail and use GetLastError</returns>

    ''' <returns>Nonzero indicates success. Zero indicates failure. To get extended error information, call GetLastError.</returns>

    ''' <returns>Nonzero indicates success. Zero indicates failure. To get extended error information, call GetLastError.</returns>

//public static extern int GetLastError();

You will need the above ProcessInfo class and may also want to use GetLastError and WaitForSingleObject.

Returns true if function succeeds; otherwise, false. To retrieve extended error information, call GetLastError

static extern Int32 GetLastError();

Declare Function GetLastError Lib "coredll.dll" () As Int32

It is recommended that you do not call the Win32 GetLastError method directly. Because of the way P/Invoke works, the error message may get reset between Win32 calls in your code. Instead, call the Marshal.GetLastWin32Error method, which can be combined with the ever useful Marshal.ThrowExceptionForHR method. See below for an example.

Int32 lastError = GetLastError();

lastError = GetLastError()

3 - SYSMEM_FAILED: Change failed. Use GetLastError to get more details.

     int error = Marshal.GetLastWin32Error();    // Equivalent to Win32 GetLastError()

WAIT_FAILED indicates failure. To get extended error information, call GetLastError.

    ''' <returns><c>True</c> on success; otherwise <c>False</c>. For extended error information, call the GetLastError() function.</returns>

    ''' If the password cannot be decrypted, the function returns FALSE, an a call to the GetLastError function will return the value ERROR_NOT_CAPABLE.</param>

    ''' <returns><c>True</c> on success; otherwise <c>False</c>. For extended error information, call the GetLastError() function.</returns>

If no error occurs, sendto returns the total number of bytes sent, which can be less than the number indicated by len. Otherwise, a value of SOCKET_ERROR is returned, and a specific error code can be retrieved by calling WSAGetLastError.

WSAGetLastError.

If no error occurs, sendto returns the total number of bytes sent, which can be less than the number indicated by len. Otherwise, a value of SOCKET_ERROR is returned, and a specific error code can be retrieved by calling WSAGetLastError.

WSAGetLastError.

static extern Int32 WSAGetLastError();

Declare Function WSAGetLastError Lib "ws2_32.dll" () As Int32

I'd go so far as to recommend always mandating SetLastError -- explicitly setting SetLastError=false, to call out the (comparatively rare) Win32 functions that don't expose a failure path through GetLastError.

                Console.WriteLine("Call to EnumDeviceDrivers failed!  To get extended error information, call GetLastError.");

                Console.WriteLine("Call to EnumDeviceDrivers failed!  To get extended error information, call GetLastError.");

                Console.WriteLine("Call to EnumDeviceDrivers failed!  To get extended error information, call GetLastError.");

                Console.WriteLine("Call to EnumDeviceDrivers failed!  To get extended error information, call GetLastError.");

Do not use GetLastError with the return values of this function.

Otherwise, if the function fails, the return value is zero. To get extended error information, call GetLastError.

static extern TODO WNetGetLastErrorA(ref int lpError,ref string lpErrorBuf,int nErrorBufSize,string lpNameBuf,int nNameBufSize);

public static extern uint WNetGetLastError(ref int lpError,StringBuilder lpErrorBuf,int nErrorBufSize,StringBuilder lpNameBuf,int nNameBufSize);

Declare Function WNetGetLastError Lib "mpr.dll" Alias "WNetGetLastErrorA" (ByRef lpError As Integer, ByVal lpErrorBuf As String, ByVal nErrorBufSize As Integer, ByVal lpNameBuf As String, ByVal nNameBufSize As Integer) As Integer

SP_COPY_NOOVERWRITE Copy only if the specified files don't currently exist in the INF directory. If the INF does currently exist, this API will fail and GetLastError returns ERROR_FILE_EXISTS. In this case, the existing INF file's filename will be placed into the appropriate field in the destination INF file's information output buffers.

in Size of the DestinationInfFileName buffer, in characters, or zero if the buffer is not specified. If DestinationInfFileName is specified and this buffer size is less than the size required to return the destination INF filename (including full path), this function will fail. In this case GetLastError will return ERROR_INSUFFICIENT_BUFFER.

The SetupCopyOEMInf function failed. For extended error information, call GetLastError.

        ErrorCode = GetLastError();

in Zero-based index to the list of interfaces in the device information set. You should first call this function with the MemberIndex parameter set to zero to obtain the first interface. Then, repeatedly increment MemberIndex and retrieve an interface until this function fails and GetLastError returns ERROR_NO_MORE_ITEMS (259).

If the function fails, the return value is zero. To get extended error information, call GetLastError.

A call to SetupDiEnumDeviceInterfaces retrieves a pointer to a structure that identifies a specific device interface in the previously retrieved DeviceInfoSet array. The call specifies a device interface by passing an array index. To retrieve information about all of the device interfaces, an application can loop through the array, incrementing the array index until the function returns zero, indicating that there are no more interfaces. The GetLastError API function then returns No more data is available.

If the function could not find a line, the return value is zero. To get extended error information, call GetLastError.

If this function finds the next line, the return value is a nonzero value. Otherwise, the return value is zero. To get extended error information, call GetLastError.

The function returns a nonzero value if it finds a matching line. Otherwise, the return value is zero. To get extended error information, call GetLastError.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

If this function is called with a ReturnBuffer of NULL and a ReturnBufferSize of zero, the function puts the buffer size needed to hold the specified data into the variable pointed to by RequiredSize. If the function succeeds in this, the return value is a nonzero value. Otherwise, the return value is zero and extended error information can be obtained by calling GetLastError. You can call the function once to get the required buffer size, allocate the necessary memory, and then call the function a second time to retrieve the data. Using this technique, you can avoid errors due to an insufficient buffer size.

The function returns a handle to the opened INF file if it is successful. Otherwise, the return value is INVALID_HANDLE_VALUE. Extended error information can be retrieved by a call to GetLastError.

If the load fails because the INF file type does not match InfClass, the function returns INVALID_HANDLE_VALUE and a call to GetLastError returns ERROR_CLASS_MISMATCH.

        printf("IcmpCreatefile returned error: %ld\n", GetLastError());

As always, only do SetLastError=true if you actually intend to call GetLastError.

/// If the function fails, the return value is zero. To get extended error information, call GetLastError.

    /// If the function fails, the return value is zero. To get extended error information, call GetLastError.

Return Values : Returns TRUE if successful, or FALSE otherwise. To get a specific error message, call GetLastError.

    [DllImport("wininet.dll", EntryPoint = "GetLastError")]

    public static extern long GetLastError();