Method '<methodname1>' cannot implement partial method '<methodname2>' because '<methodname3>' already implements it

Method '<methodname1>' cannot implement partial method '<methodname2>' because '<methodname3>' already implements it. Only one method can implement a partial method.

You cannot have two partial methods that implement the same partial method declaration. The following code causes this error.

Partial Class Product

    ' Declaration of the partial method.
    Partial Private Sub ValueChanged()
    End Sub

End Class

Partial Class Product

    ' First implementation of the partial method.
    Private Sub ValueChanged()
        MsgBox(Value was changed to " & Me.Quantity)
    End Sub

    ' Second implementation of the partial method causes this error.
    'Private Sub ValueChanged()
    '    Console.WriteLine("Quantity was changed to " & Me.Quantity)
    'End Sub

End Class

Error ID: BC31434

See Also

Concepts

Partial Methods