我在代码框中输入如下的代码：
Private Sub txtinput_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtinput.KeyPress
        Select Case e.KeyChar
            Case "0" To "9", ",", ".", "-"
            Case Else
                txtinput.Text &= ""
        End Select
    End Sub
但是在文本框中进行输入时,依然可以输入字母, why?
我要怎样改才能使它只能输入0~9的数字和逗号、小数点和负号？？？
敬请指教！！
急……