How to put this function inside a separate thread

问题

I need a little (or big) help with my form: I need to use everything inside the "Organize function" region in a separate thread.

I press a button in my form's "Start button" region to call the first sub of the "Organize function" subs; the first sub calls the second sub and the second sub calls the third sub.

I tried adding the third sub into a separate thread by myself and then using the second sub to pass the argument to the thread but all I've done is wrong.

Can someone please help me do this?

PS: I've deleted the non-important parts in this form to let you check better.

Thank you for reading.

Public Class Form1


#Region "Declarations"

        ' MediaInfo
        Dim MI As MediaInfo

        ' Thread
        Dim paused As Boolean = False

        ' Others
        Dim NameOfDirectory As String = Nothing
        Dim aFile As FileInfo

#End Region



    'thread
    Dim t As New Thread(AddressOf ThreadProc)

    Public Sub ThreadProc()
        ' Aqui debería ir  todo el sub de "organize function", bueno... son 3 subs!
        If paused = True Then MsgBox("THREAD PAUSADO")
    End Sub



#Region "Properties"
...
#End Region

#Region "Load / Close"
...
#End Region

#Region "Get Total files Function"
...
#End Region

#Region "Option checkboxes"
...
#End Region

#Region "Folder buttons"
...
#End Region

#Region "Append text function"
...
#End Region





#Region "Action buttons"

   ' pause button
    Private Sub pause_button_Click(sender As Object, e As EventArgs) Handles pause_button.Click
        paused = True
    End Sub

    ' start button
        Private Sub Button2_Click(sender As Object, e As EventArgs) Handles start_button.Click

              t.Start()

                    ' Organization process
                    NameOfDirectory = userSelectedFolderPath
                    MediaInfo(NameOfDirectory)

        End Sub

#End region





#Region "Organize function"

        Public Sub MediaInfo(Directory)
            Dim MyDirectory As DirectoryInfo
            MyDirectory = New DirectoryInfo(NameOfDirectory)
            MediaInfoWorkWithDirectory(MyDirectory)
        End Sub

        Public Sub MediaInfoWorkWithDirectory(ByVal aDir As DirectoryInfo)
            Dim nextDir As DirectoryInfo
            MediaInfoWorkWithFilesInDir(aDir)
            For Each nextDir In aDir.GetDirectories
                Using writer As StreamWriter = New StreamWriter(aDir.FullName & "\" & nextDir.Name & "\" & nextDir.Name & ".m3u", False, System.Text.Encoding.UTF8)
                    'overwrite existing playlist
                End Using
                MediaInfoWorkWithDirectory(nextDir)
            Next
        End Sub

        Public Sub MediaInfoWorkWithFilesInDir(ByVal aDir As DirectoryInfo)

            Dim aFile As FileInfo





            For Each aFile In aDir.GetFiles()

               ' hacer cosas con aFile ...

            Next

        End Sub

#End Region



End Class

回答1:

There is a Windows Forms component called BackgroundWorker that is designed specifically to offload long-running tasks from the UI thread to a background thread, leaving your form nice and responsive.

The BackgroundWorker component has an event called DoWork that is used to execute code on a separate thread. Drag the BackgroundWorker component onto your form and then do something like this:

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles start_button.Click
    NameOfDirectory = userSelectedFolderPath
    backgroundWorker1.RunWorkerAsync(NameOfDirectory)
End Sub

Private Sub BackgroundWorker1_DoWork(sender As System.Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
    Dim directoryName as string = e.Argument

    MediaInfo(directoryName)
End Sub

A couple of links that might be useful are the MSDN BackgroundWorker page and an example on Code Project.

HTH

回答2:

There are around 5 dozen ways to solve the problem. I will show just 3 of them:

Public Class Form1

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

    ' fire and forget:
    Task.Run(Sub() FooA()).ContinueWith(Sub() FooB()).ContinueWith(Sub() FooC())
    Console.WriteLine("Button1 done")

End Sub

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click

    ' fire and forget:
    Task.Run(Sub()
                 FooA()
                 FooB()
                 FooC()
             End Sub)
    Console.WriteLine("Button2 done")

End Sub

Private Async Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click

    ' wait but dont block:
    Await Task.Run(Sub()
                       FooA()
                       FooB()
                       FooC()
                   End Sub)
    Console.WriteLine("Button3 done")

End Sub

Private Sub FooA()
    Threading.Thread.Sleep(1000)
    Console.WriteLine("A")
End Sub

Private Sub FooB()
    Threading.Thread.Sleep(1000)
    Console.WriteLine("B")
End Sub

Private Sub FooC()
    Threading.Thread.Sleep(1000)
    Console.WriteLine("C")
End Sub

End Class

I would suggest the one with Await (IF FW 4.x and VS2012 is not an issue).

来源：https://stackoverflow.com/questions/13603606/how-to-put-this-function-inside-a-separate-thread