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• As a programmer, you may need to generate GUIDs (Globally Unique Identifiers) for various purposes.

As a programmer, you may need to generate GUIDs (Globally Unique Identifiers) for various purposes.

As a programmer, you may need to generate GUIDs (Globally Unique Identifiers) for various purposes. Here is how to generate a GUID in Visual

API Declarations


Data1 As Long
Data2 As Integer
Data3 As Integer
Data4(7) As Byte
End Type

Public Declare Function CoCreateGuid Lib "OLE32.DLL" (pGuid As GUID) As Long
Public Const S_OK = 0 ' return value from CoCreateGuid



Rate As a programmer, you may need to generate GUIDs (Globally Unique Identifiers) for various purposes.

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(2(2 Vote))

    
    Dim lResult As Long
    Dim lguid As GUID
    Dim MyguidString As String
    Dim MyGuidString1 As String
    Dim MyGuidString2 As String
    Dim MyGuidString3 As String
    Dim DataLen As Integer
    Dim StringLen As Integer
    Dim i%
    
    On Error GoTo error_olemsg
    
    lResult = CoCreateGuid(lguid)
    
    If lResult = S_OK Then
        MyGuidString1 = Hex$(lguid.Data1)
        StringLen = Len(MyGuidString1)
        DataLen = Len(lguid.Data1)
        MyGuidString1 = LeadingZeros(2 * DataLen, StringLen) & MyGuidString1        'First 4 bytes (8 hex digits)
        
        MyGuidString2 = Hex$(lguid.Data2)
        StringLen = Len(MyGuidString2)
        DataLen = Len(lguid.Data2)
        MyGuidString2 = LeadingZeros(2 * DataLen, StringLen) & Trim$(MyGuidString2)        'Next 2 bytes (4 hex digits)
        
        MyGuidString3 = Hex$(lguid.Data3)
        StringLen = Len(MyGuidString3)
        DataLen = Len(lguid.Data3)
        MyGuidString3 = LeadingZeros(2 * DataLen, StringLen) & Trim$(MyGuidString3)        'Next 2 bytes (4 hex digits)
        
        GetGUID = MyGuidString1 & MyGuidString2 & MyGuidString3
        
        For i% = 0 To 7
           MyguidString = MyguidString & Format$(Hex$(lguid.Data4(i%)), "00")
        Next i%
        
        'MyGuidString contains last 8 bytes of Guid (16 hex digits)
        GetGUID = GetGUID & MyguidString
    Else
        GetGUID = "00000000" ' return zeros if function unsuccessful
    End If
    
    Exit Function

error_olemsg:
         MsgBox "Error " & Str(Err) & ": " & Error$(Err)
         GetGUID = "00000000"
         Exit Function

End Function

Function LeadingZeros(ExpectedLen As Integer, ActualLen As Integer) As String
    LeadingZeros = String$(ExpectedLen - ActualLen, "0")
End Function