Visual Basic Programming Code Examples

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Return the error message associated with Err.LastDllError



Return the error message associated with Err.LastDllError

The following code will return an error message associated with a particular DLL error number:


Private Declare Function FormatMessage Lib "kernel32" Alias "FormatMessageA" (ByVal dwFlags As Long, lpSource As Any, ByVal dwMessageId As Long, ByVal dwLanguageId As Long, ByVal lpBuffer As String, ByVal nSize As Long, Arguments As Long) As Long

'Purpose     :  Return the error message associated with LastDLLError
'Inputs      :  [lLastDLLError]               The error number of the last DLL error (from Err.LastDllError)
'Outputs     :  Returns the error message associated with the DLL error number


Public Function ErrorDescriptionDLL(Optional ByVal lLastDLLError As Long) As String
    Dim sBuff As String * 256
    Dim lCount As Long
    Const FORMAT_MESSAGE_ALLOCATE_BUFFER = &H100, FORMAT_MESSAGE_ARGUMENT_ARRAY = &H2000
    Const FORMAT_MESSAGE_FROM_HMODULE = &H800, FORMAT_MESSAGE_FROM_STRING = &H400
    Const FORMAT_MESSAGE_FROM_SYSTEM = &H1000, FORMAT_MESSAGE_IGNORE_INSERTS = &H200
    Const FORMAT_MESSAGE_MAX_WIDTH_MASK = &HFF

    If lLastDLLError = 0 Then 
        'Use Err object to get dll error number
        lLastDLLError = Err.LastDllError    
    End If

    lCount = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM Or FORMAT_MESSAGE_IGNORE_INSERTS, 0, lLastDLLError, 0&, sBuff, Len(sBuff), ByVal 0)
    If lCount Then
        ErrorDescriptionDLL = Left$(sBuff, lCount - 2)    'Remove line feeds
    End If
    
End Function