VB Snippet - Get last API error description

[MerrionComputin]

When an API call is executed in VB and it has an error it usually sets the Err.LastDllError property to a number. You can decode this number to a meaningful description of the error as follows:

'\ API Error decoding
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
 
Public Function LastSystemError() As String
 
Const FORMAT_MESSAGE_FROM_SYSTEM = &H1000
Dim sError As String * 500 '\\ Preinitilise a string buffer to put any error message into
Dim lErrNum As Long
Dim lErrMsg As Long
 
lErrNum = Err.LastDllError
 
lErrMsg = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, ByVal 0&, lErrNum, 0, sError, Len(sError), 0)
 
LastSystemError = Trim(sError)
 
End Function