Question

我在VB.Net工作，我需要暂停一个线程，因为它等待另一个完成。

我看到了一个非常接近的问题，但似乎无法弄明白（并且无法评论该帖子Pause/Resume loop in Background worker）

我的情况是我有2名背景工作者。 Worker1正在将fileNames传递给Worker2，后者处理文件。如果Worker2尚未完成，我需要暂停Worker1。即Worker1仅在Worker2完成后释放下一个fileName

关于如何做到这一点的任何想法？

来自@ user1666788的评论后的工作代码

下面的代码是针对两个背景工作者的上述情况，其中一个人必须等待另一个完成才能继续。

Dim isFinished as boolean
Dim currentFiile as integer

Private Sub StartWork_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles StartWork.Click
    bgWorker1.WorkerSupportsCancellation = True
    isFinished = True
    currentFile = 0
    bgWorker1.RunWorkerAsync()
End Sub

Private Sub bgWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles bgWorker1.DoWork
    If isFinished = False Then
        bgWorker1.CancelAsync()
    End If
    isFinished = False
    For i = currentFile To fileNames.Count - 1
        Dim fileName As String = fileNames(i)
        LoadRules(myValidator.GetFileType(fileName))
        If i = fileNames.Count Then bgWorker1.CancelAsync()
        Exit Sub
    Next
End Sub

Private Function LoadRules(ByVal fileType As String) As Boolean
    ' Function to load some rules for file processing
    Try

        ' Start Thread for actual file processing using bgworker2
        bgWorker2.WorkerSupportsCancellation = True
        bgWorker2.RunWorkerAsync()
        Return True
    Catch ex As Exception

    End Try
End Function

Private Sub bgWorker2_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles bgWorker2.DoWork

    Try

         ' Do your thing here
         ' for x is 0 to 1million
         ' next

        ' Mark is finished to true
        isFinished = True

        ' Set currentFile
        currentFile += 1

        ' The bgWorker1 is restarted when bgWorker2 has finished.
        ' Note however that bgWorker1 will "Continue" where it left off due to the property "currentFile"
        bgWorker1.RunWorkerAsync()

        '++++++++++++++++++++++++++++++++++++
    Catch ex As Exception

    End Try
End Sub

你去吧。它按预期工作。现在需要弄清楚如何“监视”将文件写入磁盘的进度，这样我就可以在文件完全创建后开始另一个进程.....

Answer 1

我有类似的问题。从我被VS告知的事情来看，它无法完成。但是我找到了一种绕过子程序的方法，用于暂停/恢复不再使用的线程。

最简单的方法是检查进度，如果它仍在工作，则结束通话。这是一个例子，假设S1是你的第一个线程，S2是你的第二个。

sub S1()

if(processingfile)then exit sub

'Insert code here for sending next file for processing

end sub

sub S2()
processingfile = true

'Insert code for processing files

processingfile = false

end sub

这或多或少是我解决问题的方法。我希望我的建议有所帮助：）

哦，还有一件事，你可能想要在检查文件是否正在处理之前睡眠第一个线程，这样它就不会耗尽一大堆CPU的功率。但这只是一个猜测，我没有在没有短暂的睡眠期间尝试过它

暂停并恢复线程（后台工作者）

1 个答案: