急：线程委托问题，请大侠指点。
Imports System.Data.SqlClient
Public Class ggbf
Public temp As String = ""
Delegate Sub setG(ByVal i As Integer)
Dim xc As New System.Threading.Thread(AddressOf displayG)’播放图片线程
Dim receiveing As New System.Threading.Thread(AddressOf setreceive)‘收取网络数据线程
Delegate Sub setcloses(ByVal x1 As Form, ByVal y1 As Boolean)
<Runtime.InteropServices.DllImport("DllTest.dll")> _
Shared Function receive() As String‘DLL里的线程，用来收取网络发来的数据
End Function
<Runtime.InteropServices.DllImport("DllTest.dll")> _
Shared Sub sendTo(ByVal x As String)‘用来发送数据
End Sub
<Runtime.InteropServices.DllImport("DllTest.dll")> _
Shared Sub clean()
End Sub
<Runtime.InteropServices.DllImport("DllTest.dll")> _
Shared Sub quit()
End Sub
<Runtime.InteropServices.DllImport("DllTest.dll")> _
Shared Sub start()'初始化网络端口
End Sub
Private Sub ggbf_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.Location = New Point(0, 0)
My.Forms.cljg.Show()
xc.Start()
start()
receiveing.Start()
End Sub
Public Sub displayG(ByVal x As Integer)
setxc("select * from [guanggao] Order By u_id ")
If settable.Rows.Count = 0 Then
MsgBox("无广告内容！")
Else
For i As Integer = 0 To settable.Rows.Count - 1
If i = settable.Rows.Count - 1 Then
i = 0
End If
readbytephoto(settable.Rows(i).Item("u_tp"), Picture)
System.Threading.Thread.Sleep(5000) '延时一秒
Next i
End If
End Sub
Sub setreceive()
Dim a As Boolean = True
While a
Dim str As String = receive()‘收网络数据，如果没有数据，这个线程会卡在那。
System.Threading.Thread.Sleep(10)
str = Mid(str, 1, 5)
If str = "hello" Then
sendTo("hello")
End If
Select Case Mid(str, 2, 1)
Case "#"
sendTo("^#OK" & vbCr)
a = False
setclose(My.Forms.Form6, True)
End Select
End While
End Sub
Private Sub setclose(ByVal x As Form, ByVal y As Boolean)
If x.InvokeRequired Then
Dim d As New setcloses(AddressOf setclose)
Me.Invoke(d, New Object() {x, y})
Else
If y Then
x.Show()
Else
x.Close()
End If
End If
End Sub
Private Sub Form1_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
xc = Nothing
receiveing = Nothing
End Sub
End Class
执行CASE #时为什么不能完成打开一个新窗体并关闭me的操作呢，我改过了，也不行，不是打不开新窗体就是打开了鼠标状态是忙，哪位高手帮我看一眼是什么情况，谢谢了。

[解决办法]
Private Sub setclose(ByVal x As Form, ByVal y As Boolean)
If x.InvokeRequired Then
Dim d As New setcloses(AddressOf setclose)
Me.Invoke(d, New Object() {x, y})--->>>>x.Invoke(d, New Object() {x, y}
Else
If y Then
x.Show()
Else
x.Close()
End If
End If
End Sub