我在论坛中学习了别人的一段代码，可以通过双击增加三类控件，即label、line、PictureBox，我也学习一下，在程序中增加了增加button类型的控件，却实现不了我想要的功能，不知道为什么？

Dim ctl As Object
Select Case e.Sender.Gettype.Name
    Case "Label"
        ctl = e.Form.CreateControl("Test" & Format(Date.now,"ddhhmmss"), ControlTypeEnum.Label)
        ctl.Text = "Test" & Format(Date.now,"ddhhmmss")
        ctl.Font = new Font("黑体", 15)
        ctl.autosize = True
   Case "button"
        ctl = e.Form.CreateControl("Test" & Format(Date.now,"ddhhmmss"), ControlTypeEnum.button)
        ctl.Text = "Test" & Format(Date.now,"ddhhmmss")
        ctl.Font = new Font("黑体", 15)
        ctl.autosize = True

 Case "Line"
        ctl = e.Form.CreateControl("Test" & Format(Date.now,"ddhhmmss"), ControlTypeEnum.line)
        ctl.ThickNess = 20
        ctl.LineColor = Color.Red
    Case "PictureBox"
        ctl = e.Form.CreateControl("Test" & Format(Date.now,"ddhhmmss"), ControlTypeEnum.PictureBox)
End Select

If ctl IsNot Nothing Then
    Dim body As object = e.Form.controls("pnl_body")
    ctl.Left = 100
    ctl.Top = 100
    Dim dr As DataRow = DataTables("表A").Find("第一列=\'" & ctl.Name & "\'")
    If dr Is Nothing Then
        Dim r As Row = Tables("表A").AddNew
        r("第一列")=ctl.Name
        r("第二列") = ctl.Left
        r("第三列")=ctl.top
        r("第四列")= e.Sender.Gettype.Name
        r.Save
    End If
    body.AddControl(ctl)
End If