主题：怎么样理解窗口停止绘制

Ports("COM1").Write(CHR(73))
Ports("COM1").Write(CHR(13))
Ports("COM1").Write(CHR(10))
'Ports("COM1").Write("SI")
'Ports("COM1").Write("CRLF")
Dim t As WinForm.TextBox = e.Form.Controls("t1")

Dim s As String=Ports("COM1").ReadExisting

dim jg as string = Functions.Execute("提取结果",s)

if jg = t.text then return '如果结果和文本框内容一致就返回

t.Text= jg

If s.Contains("S D")  Then
    t.BackColor= Color.Red

Else
    t.BackColor=Color.Gray

end if

Functions.Execute("写库",1)