VB.NET Class.6 (亂數)

練習一：取10個亂數印出並顯示大於60的個數

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Public Class Form1

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click

        Label1.Text = ""

        Dim a(9) As Double

        Dim i As Integer

        Dim x As Integer = 0

        Randomize()              //有這行才能夠使 Rnd()真正實現亂數

        For i = 0 To a.Length - 1

            a(i) = Math.Floor(Rnd() * 100) + 1                  //Math.Floor() 為絕對值取法
                                                                                         //Rnd() 為亂數取值 0 ~ 1 之間的小數

            If a(i) >= 60 Then

                x += 1

            End If

        Next

        For i = 0 To a.Length - 1

            Label1.Text = Label1.Text & i + 1 & ". " & a(i) & vbCr

        Next

        Label1.Text = Label1.Text & "及格的有 " & x & " 個"

    End Sub

End Class

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練習二：改變程式預設屬性
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1. 滑鼠在紅色區域內點兩下

2. 進入下列畫面後右上角選擇 "Activated"

3. 接著在以下出現的 "Form1_Activated" 中撰寫程式就能在程式起始時完成屬性設定

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Private Sub Form1_Activated(sender As Object, e As System.EventArgs) Handles Me.Activated

        Label1.Text = ""

        Label1.ForeColor = Color.Red

    End Sub

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4. 結果