疑難排解例外狀況：System.ArgumentException
提供給方法的引數中，如果至少有一個不符合方法的參數規格，就會擲回 ArgumentException 例外狀況。
在下列範例中，當傳送給 DivideByTwo 方法的引數不是偶數時，會擲回例外狀況。
Module Module1
Sub Main()
' ArgumentException is not thrown in DivideByTwo because 10 is
' an even number.
Console.WriteLine("10 divided by 2 is {0}", DivideByTwo(10))
Try
' ArgumentException is thrown in DivideByTwo because 7 is
' not an even number.
Console.WriteLine("7 divided by 2 is {0}", DivideByTwo(7))
Catch argEx As ArgumentException
' Tell the user which problem is encountered.
Console.WriteLine("7 cannot be evenly divided by 2.")
Console.WriteLine("Exception message: " & argEx.Message)
End Try
' Uncomment the next statement to see what happens if you call
' DivideByTwo directly.
'Console.WriteLine(DivideByTwo(7))
End Sub
Function DivideByTwo(ByVal num As Integer) As Integer
' If num is an odd number, throw an ArgumentException. The
' ArgumentException class provides a number of constructors
' that you can choose from.
If num Mod 2 = 1 Then
Throw New ArgumentException("Argument for num must be" & _
" an even number.")
End If
' Value of num is even, so return half of its value.
Return num / 2
End Function
End Module
ArgumentException 類別的所有執行個體都應該包括指定哪個引數無效、可接受值的範圍等相關資訊。 如果有更精確的例外狀況 (例如 ArgumentNullException 或 ArgumentOutOfRangeException) 能夠更正確地描述狀況，則應改用這種例外狀況，取代 ArgumentException。
如需此例外狀況的詳細資訊，包括其他語言的範例，請參閱 ArgumentException。 如需其他建構函式 (Constructor) 的清單，請參閱 ArgumentException()。