vb.net限制輸入數字並只到小數點後2位

Private Sub txtRatio_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtRatio.KeyPress

        '輸入為數字，小數點或backspace
        If Char.IsDigit(e.KeyChar) Or e.KeyChar = "." Or e.KeyChar = Chr(8) Then 'Backspace: 
            '輸入的小數點為唯一
            If e.KeyChar = "." And InStr(CType(sender, System.Windows.Forms.TextBox).Text, ".") > 0 Then
                e.Handled = True
            Else
                '小數最多2位
                If e.KeyChar <> Chr(8) And InStr(CType(sender, System.Windows.Forms.TextBox).Text, ".") > 0 Then
                    Dim sAry() As String = CType(sender, System.Windows.Forms.TextBox).Text.Split(".")
                    If sAry(1).Length >= 2 Then
                        e.Handled = True
                    Else
                        e.Handled = False
                    End If
                Else
                    e.Handled = False
                End If
            End If

            '輸入的負號是否在第一位
        ElseIf e.KeyChar = "-" And CType(sender, System.Windows.Forms.TextBox).Text = "" Then
            e.Handled = False
        Else
            e.Handled = True
        End If

    End Sub