按钮单击时暂停线程单击按钮时恢复

Question

我有一个从某些网站获取数据的循环，该循环大约需要一个小时才能获取数据并将其填充到数据库中，这个循环在一个线程中，我想添加一个按钮来暂停线程，直到再次单击按钮并从停止的地方恢复。 我怎样才能安全地做到这一点？

Answer 1

这是一个简单的 Windows 控制台应用程序；它使用布尔标志来指示线程是否应该处理。我希望这能为您指明正确的方向。

Module Module1

    Private _ThreadControl_Run As Boolean = False

    Sub Main()
        Dim thread As New System.Threading.Thread(AddressOf ThreadWorker)
        thread.IsBackground = True
        thread.Start()

        _ThreadControl_Run = True
        Console.WriteLine("Main() _ThreadControl_Run = " & _ThreadControl_Run.ToString())
        System.Threading.Thread.Sleep(1000)

        _ThreadControl_Run = False
        Console.WriteLine("Main() _ThreadControl_Run = " & _ThreadControl_Run.ToString())
        System.Threading.Thread.Sleep(1000)

        _ThreadControl_Run = True
        Console.WriteLine("Main() _ThreadControl_Run = " & _ThreadControl_Run.ToString())
        System.Threading.Thread.Sleep(1000)

        _ThreadControl_Run = False
        Console.WriteLine("Main() _ThreadControl_Run = " & _ThreadControl_Run.ToString())
        System.Threading.Thread.Sleep(1000)
    End Sub

    Private Sub ThreadWorker()
        Do While True
            If (_ThreadControl_Run) Then
                Console.WriteLine("     ThreadWorker()")
                System.Threading.Thread.Sleep(100)
            End If
        Loop
    End Sub

End Module

Answer 2

试试这个：

Public Sub PauseThreadButton_Click(sender As System.Object, e As System.EventArgs) Handles PauseThreadButton.Click
    'REM: Next line puts your thread in a suspended state
    TheThread.Suspend()
End Sub

继续：

Public Sub ResumeThreadButton_Click(sender As System.Object, e As System.EventArgs) Handles ResumeThreadButton.Click
    'REM: Next line resumes your thread
    TheThread.Resume()
End Sub