Excel VBA 亂數Rnd

Function Fn1_大樂透電腦選號()
    '陣列必需指定常數
        Const All_Ball = 49
        Const ShowBall = 6
    '以下程式碼引用凸槌的木工
        Dim i%, num%
        Dim a(1 To All_Ball) As Boolean
        Dim n(1 To ShowBall) As Integer
        Erase a  '清除a陣列
        For i = 1 To ShowBall
            num = Int(All_Ball * Rnd + 1) '取得亂數(可能重覆)
            Do While a(num) = True '若陣列a內已加入num則執行下句:
                num = Int(All_Ball * Rnd + 1) '重新取得亂數
            Loop
            a(num) = True '把num加入陣列
            n(i) = num
        Next i
    '
        Range("A1:f1") = n
End Function