当我单击按钮时，选择案例将不做任何事情

Question

堆栈溢出。我正在努力制作括号计划。我希望能够使用Select Case来告诉它是谁赢的。

我制作了以下代码：

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim gen1 As New System.Random
        Dim random As Integer
        Dim B1 As String
        random = gen1.Next(0, 101)
        Select Case B1
            Case random <= 50
                MessageBox.Show("less than or = to 50")
            Case random >= 51
                MessageBox.Show("More than or = to 51")
        End Select
    End Sub

但是，当我单击按钮时，代码无需做任何事情。没有消息框出现，也没有任何消息。此代码中有什么问题？我已经使用Dim gen1 As New System.Random和Dim random As Integer正确设置了随机生成器代码，但是什么也没有发生。感谢您的帮助！

Answer 1

您尚未将B1变量设置为任何东西。如果将代码修改为这样的事情：

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim gen1 As New System.Random
    Dim random As Integer
    Dim B1 As String
    random = gen1.Next(0, 101)
    Select Case random
        Case Is <= 50
            MessageBox.Show("less than or = to 50")
        Case Else
            MessageBox.Show("More than or = to 51")
    End Select
End Sub

您可以在此处找到更多信息选择案例帮助

您可以将其重写以使用if语句

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim gen1 As New System.Random
    if gen1.Next(0, 101) <= 50 then
        MessageBox.Show("less than or = to 50")
    else
        MessageBox.Show("More than or = to 51")
    End if
End Sub