代码添加控件的问题

VB.NET code

        Dim x, y As Integer        x = TextBox1.Left        y = TextBox1.Top        For i As Integer = 2 To ComboBox1.Text            Dim tbox As New TextBox            tbox.Location = New System.Drawing.Point(x + 20, y)            tbox.Name = "tbox" & i.ToString            tbox.Size = TextBox1.Size            tbox.Visible = True        Next i        Me.Refresh()

上面是代码，但是窗体显示不出来新建的TextBox，请问是因为什么问题？

[解决办法]
Me.Controls.Add(tbox)