Get Error Messages Directly from the System
Sample :
Call APIError
' *** Or
Debug.Print ReturnAPIError(53)
' *** Return : The network path was not found.
' #VBIDEUtils#************************************************** ' * Programmer Name : Waty Thierry ' * Web Site : www.geocities.com/ResearchTriangle/6311/ ' * E-Mail : waty.thierry@usa.net ' * Date : 12/10/1998 ' * Time : 20:20 ' * Module Name : APIError_Module ' * Module Filename : APIError.bas ' ************************************************************** ' * Comments : ' * Used to get error messages directly from the ' * system instead of hard-coding them ' * ' * ' **************************************************************Option Explicit
Private Const FORMAT_MESSAGE_FROM_SYSTEM = &H1000 Private Const FORMAT_MESSAGE_IGNORE_INSERTS = &H200
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
' *** Status Codes Public Const INVALID_HANDLE_VALUE = -1& Public Const ERROR_SUCCESS = 0&
Public Function ReturnAPIError(ErrorCode As Long) As String ' #VBIDEUtils#*********************************************** ' * Programmer Name : Waty Thierry ' * Web Site : www.geocities.com/ResearchTriangle/6311/ ' * E-Mail : waty.thierry@usa.net ' * Date : 12/10/1998 ' * Time : 20:21 ' * Module Name : APIError_Module ' * Module Filename : APIError.bas ' * Procedure Name : ReturnAPIError ' * Parameters : ' * ErrorCode As Long ' *********************************************************** ' * Comments : ' * Takes an API error number, and returns ' * a descriptive text string of the error ' * ' ***********************************************************
Dim sBuffer As String
' *** Allocate the string, then get the system to ' *** tell us the error message associated with ' *** this error number sBuffer = String(256, 0) FormatMessage FORMAT_MESSAGE_FROM_SYSTEM Or _ FORMAT_MESSAGE_IGNORE_INSERTS, 0&, ErrorCode, 0&, sBuffer, Len(sBuffer), 0&
' *** Strip the last null, then the last CrLf pair if it exists sBuffer = Left(sBuffer, InStr(sBuffer, vbNullChar) - 1) If Right$(sBuffer, 2) = Chr$(13) & Chr$(10) Then sBuffer = Mid$(sBuffer, 1, Len(sBuffer) - 2) End If
ReturnAPIError = sBuffer
End Function
Public Sub APIError() ' #VBIDEUtils#*********************************************** ' * Programmer Name : Waty Thierry ' * Web Site : www.geocities.com/ResearchTriangle/6311/ ' * E-Mail : waty.thierry@usa.net ' * Date : 12/10/1998 ' * Time : 20:35 ' * Module Name : APIError_Module ' * Module Filename : APIError.bas ' * Procedure Name : APIError ' * Parameters : ' *********************************************************** ' * Comments : ' * Takes an API error number, and returns ' * a descriptive text string of the error ' * ' ***********************************************************
Dim sError As String On Error GoTo ERROR_APIError sError = InputBox("Enter the error number", _ "Returns API error") If IsNumeric(sError) = False Then Exit Sub MsgBox ReturnAPIError(CLng(sError)), vbInformation + vbOKOnly, _ "Error n " & sError Exit Sub ERROR_APIError: MsgBox "Error n " & sError & vbCrLf & _ " Invalid error number" & vbCrLf & _ "You have to give another one", _ vbCritical + vbOKOnly, "Error n " & sError End Sub

Comments
How to use unlimmited buffer
Posted by Legacy on 08/27/2002 12:00amOriginally posted by: yoram
change lpBuffer to Byref lpBuffer as long
so
Private Declare Function FormatMessage Lib "kernel32" Alias "FormatMessageA" (ByVal dwFlags As Long, lpSource As Any, ByVal dwMessageId As Long, ByVal dwLanguageId As Long, ByRef lpBuffer As Long, ByVal nSize As Long, Arguments As Long) As Long
use th flag
Private Const FORMAT_MESSAGE_ALLOCATE_BUFFER = &H100
now
Dim buffer as long
FormatMessage FORMAT_MESSAGE_FROM_SYSTEM Or FORMAT_MESSAGE_ALLOCATE_BUFFER, _
0, msgId, 0, buffer, 0, 0
now you post the string by
Reply' Note that this is not vb msgbox but an API function
MessageBox(0, buffer, Caption, mbType)
end then
' Enother API function
LocalFree buffer
More on API errors and Visual basic
Posted by Legacy on 02/14/2000 12:00amOriginally posted by: Duncan Jones
When testing for API errors in VB, do not use the GetLastError() api call as Visual basic itself may perform any number of API functions which will reset this value behind the scenes.
ReplyFortunately the App object has a "LastDLLError" member in VB5 which you can use instead.