VB.NET 小程序 2

Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim a() As Char
        Dim i, j, k As Integer
        i =  : j =  : k =
        a = InputBox("请输入字符串", "输入")

        For b As Integer =  To Len(a) -
            Select Case a(b)
                Case "a" To "z"
                    i +=
                Case "A" To "Z"
                    j +=
                Case "" To ""
                    k +=
            End Select
        Next
        Label1.Text = "小写字母： " & i & Chr() & "大学字母： " & j & Chr() & "数字：     " & k
    End Sub
End Class