Vb.net 需要帮助重写foreach和do-until循环吗

所以我试图重新编码，因为它不能正常工作：

如您所见，上面的代码首先拆分“|”，并将它们分别添加到列表中。 然后我们分割其他内容，使其成为一个完美的url，然后通过webkitbrowser导航到它。。。并使用thread.sleep（Idk，如果可以的话）等待15秒，然后在foreach和do-until循环中将其从链接列表中删除。那有什么问题？它不能正常工作WebKit浏览器只是挂起了

注意：加载表单时会调用子StartTrafficExchange（）

有人能告诉我上面的代码有什么问题吗？有没有其他方法可以让它工作

---

-谢谢-

首先，这不是很重要，但代码不一致，您使用的是

C#

实践，但您使用的是

VB.NET

，然后删除字符串附件上的所有

+

运算符，并用

&

替换它们

其次，如果您的目的是等待网页完全加载，那么使用

Sleep

方法是不行的，您需要使用浏览器控件的

WebBrowserDocumentCompleted

事件（我不知道

WebKitBrowser

的确切事件名称）

您可以编写一个名为

NavigateAndWait

的方法，并使用它而不是使用

WebKitBrowser.Navigate

方法来简化操作

我给您举一个默认

WebBrowser

控件的示例：

Private WebPageLoaded As Boolean = False

''' <summary>
''' Navigates to an url and waits the page to be loaded.
''' </summary>
''' <param name="url">Indicates the url to navigate.</param>
''' <param name="newWindow">Indicates whether the url should open into a new browser window.</param>
Private Sub NavigateAndWait(ByVal Browser As WebBrowser,
                           ByVal url As String,
                           Optional newWindow As Boolean = False)

    Me.WebPageLoaded = False

    AddHandler Browser.DocumentCompleted, AddressOf WebBrowserDocumentCompleted
    Browser.Navigate(url, newWindow)

    Do Until Me.WebPageLoaded
        Application.DoEvents()
    Loop

    RemoveHandler Browser.DocumentCompleted, AddressOf WebBrowserDocumentCompleted

End Sub

' WebBrowser [DocumentCompleted]
Private Sub WebBrowserDocumentCompleted(ByVal sender As Object, e As WebBrowserDocumentCompletedEventArgs)
    Me.WebPageLoaded = True
End Sub

---

假设

linklist

不是实际的

LinkedList

，而是一个

List（Of T）

或列表控件的列表，则可以替换此代码块：

    Dim filterstring As String() = downloadstring.ReadToEnd.Split("|")
    For Each stirngman As String In filterstring
        linklist.Items.Add(stirngman)
    Next

为此：

Dim filter As String() = downloadstring.ReadToEnd.Split("|")
linklist.AddRange(filter)

它做同样的事情，只是速度更快，占用的内存更少

接下来，向上移动（如紧跟在

AddRange

之后）：

我本打算输入为什么要进行各种更改，但下面是我将要重构的整个例程：

Private Sub StartTrafficExchange()
  ' Performing one split here that removes everything that needs
  ' to go will be faster, take less memory, won't have to be
  ' touched as many times
  Dim filter As String() = downloadstring.ReadToEnd.Split("``[TIER4]|")
  linklist.AddRange(filter)

  ' Set your maximum value so it knows when it is full
  ProgressBarX1.Maximum = linklist.Items.Count

  ' Create a counter to let us know how many items 
  ' have been processed
  Dim counter As Int = 0
  Dim currentURL As String = String.Empty

  Do While linklist.Items.Count > 0
    ' Get the current URL from our list
    currentURL = linklist.Items(counter)

    LabelX1.Text = String.Format("Navigating To [TIER4] {0}", currentURL)
    LabelX1.Refresh() ' Allow the label to update

    ' This is only good if you have a debugger turned on
    ' or are running from the IDE
    Debug.WriteLine(currentURL)

    WebkitBrowser1.Navigate(currentURL)

    ' Not a good idea as it will block the UI
    ' from responding. If you need a delay that
    ' doesn't appear to lock up the UI, implement
    ' a timer in a loop
    Thread.Sleep(15000)

    ' Increment the counter, then update the progressbar
    counter += 1
    ProgressBarX1.Value = counter
    ProgressBarX1.Refresh() ' Allow the progressbar to update
  Loop

  ' When you are through getting all of the URLs,
  ' clear the list just one time
  linklist.Items.Clear()

  ' Make recursive call to this sub
  ' You should limit the number of recursions
  ' somehow so you don't run out of stack space
  StartTrafficExchange
End Sub

如果要暂停进程并阻止UI，请使用以下命令：

' Create a new timer object that will run for 1/10 of second
Dim timr As New Timer(100)

' Run this for 150 times at .1 seconds will
' give you a 15 second pause and still leave
' the UI responsive
For iLoop As Integer = 0 To 150
  ' Start the timer for .1 seconds
  timr.Start()

  ' This tells everything on the form to process updates
  DoEvents()
Next

---

这是因为你的Thread.Sleep（）你的webkitbrowser是免费的。似乎有很多非常相似的字符串处理可以将数组拆分多次，而一次就可以了。谢谢，伙计。但是你能告诉我如何在一个循环中实现计时器吗？我就是这么做的。查看更新。用下面的示例代码替换这一行

Thread.Sleep（15000）

。与在循环中使用计时器相比，它不能像新计时器（15000）一样变暗吗？可以，但它实际上与

Thread.Sleep（15000）

相同。您需要较短的时间运行

DoEvents（）

，以允许应用程序处理可能同时发生的任何其他事情。请尝试在Dim语句中将计时器更改为System.Timers.Timer。谢谢，但在我的情况下，我不应该只等待站点加载，而应该等待大约15-20秒。

Dim filter As String() = downloadstring.ReadToEnd.Split("|")
linklist.AddRange(filter)

ProgressBarX1.Maximum = linklist.Items.Count

Private Sub StartTrafficExchange()
  ' Performing one split here that removes everything that needs
  ' to go will be faster, take less memory, won't have to be
  ' touched as many times
  Dim filter As String() = downloadstring.ReadToEnd.Split("``[TIER4]|")
  linklist.AddRange(filter)

  ' Set your maximum value so it knows when it is full
  ProgressBarX1.Maximum = linklist.Items.Count

  ' Create a counter to let us know how many items 
  ' have been processed
  Dim counter As Int = 0
  Dim currentURL As String = String.Empty

  Do While linklist.Items.Count > 0
    ' Get the current URL from our list
    currentURL = linklist.Items(counter)

    LabelX1.Text = String.Format("Navigating To [TIER4] {0}", currentURL)
    LabelX1.Refresh() ' Allow the label to update

    ' This is only good if you have a debugger turned on
    ' or are running from the IDE
    Debug.WriteLine(currentURL)

    WebkitBrowser1.Navigate(currentURL)

    ' Not a good idea as it will block the UI
    ' from responding. If you need a delay that
    ' doesn't appear to lock up the UI, implement
    ' a timer in a loop
    Thread.Sleep(15000)

    ' Increment the counter, then update the progressbar
    counter += 1
    ProgressBarX1.Value = counter
    ProgressBarX1.Refresh() ' Allow the progressbar to update
  Loop

  ' When you are through getting all of the URLs,
  ' clear the list just one time
  linklist.Items.Clear()

  ' Make recursive call to this sub
  ' You should limit the number of recursions
  ' somehow so you don't run out of stack space
  StartTrafficExchange
End Sub

' Create a new timer object that will run for 1/10 of second
Dim timr As New Timer(100)

' Run this for 150 times at .1 seconds will
' give you a 15 second pause and still leave
' the UI responsive
For iLoop As Integer = 0 To 150
  ' Start the timer for .1 seconds
  timr.Start()

  ' This tells everything on the form to process updates
  DoEvents()
Next