Web浏览器在VB .net中的线程

Question

我试图限制在vb.net中打开webbrowser的时间;经过大量搜索后的结论似乎是线程！我试过下面的代码;这包括我试过的两种方法，但没有任何效果; 我试图在另一个线程中在10秒内打开网站，如果网站没有回复，那么去下一个网站并丢弃那个;我的代码如下： 第一次尝试：

Option Explicit On
  Option Strict On
  Imports System.Threading

 Public Class Form1
Dim WorkerThread As Thread
Dim StopThread As Boolean = True

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    MessageBox.Show(" ************************** This is the MAIN thread ************************** ")
End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    MessageBox.Show(" ************************** This is the SECOND thread ************************** ")
    If StopThread = False Then
        StopThread = True
    Else
        StopThread = False
        WorkerThread = New Thread(AddressOf Navigate)
        WorkerThread.IsBackground = True
        WorkerThread.Start()
    End If
End Sub

Sub Navigate()
    WebBrowser1.Navigate("http://www.mekdam.com")
    While WebBrowser1.ReadyState <> WebBrowserReadyState.Complete
        Application.DoEvents()
    End While
End Sub

End Class

第二次审判

    Option Explicit On
    Option Strict On
    Imports System.Threading

  Public Class Form1
Dim WorkerThread As Thread
Dim StopThread As Boolean = True

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    MessageBox.Show(" ************************** This is the MAIN thread ************************** ")
End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    MessageBox.Show(" ************************** This is the SECOND thread ************************** ")
    If StopThread = False Then
        StopThread = True
    Else
        StopThread = False
        WorkerThread = New Thread(AddressOf Navigate)
        WorkerThread.IsBackground = True
        WorkerThread.Start()
    End If
End Sub

Sub Navigate()
    WebBrowser1.Navigate("http://www.mekdam.com")
    While WebBrowser1.ReadyState <> WebBrowserReadyState.Complete
        Application.DoEvents()
    End While
End Sub

End Class