在VB.NET中用於YouTube DirectUpload的BackgroundWorker？

Question

我試圖將我的服務器上的視頻直接上傳到YouTube。當用戶添加視頻時，它會被複制到YouTube。

添加視頻的用戶操作應該開始上傳過程，這可能需要一段時間。這種形式，即使是異步形式，也不應該坐在那裏等待這種情況發生。它應該剛剛開始，並允許用戶繼續前進，相信它正在後臺處理。

爲了做到這一點，我試圖使用system.threading.backgroundworker。我希望這個過程能夠開始，網絡應用程序將繼續前進。不是。它正在掛起，無論是異步還是完整回發，並且在返回並更新lblmsg.text之前等待上傳完成。

是否有不同的方式我應該去做這件事，所以用戶可以啓動上傳程序，而不是等待它完成？這是我到目前爲止的代碼：

Sub up_load(s As Object, e As EventArgs) 
    Dim worker As BackgroundWorker = New BackgroundWorker 

    worker.WorkerReportsProgress = True 
    worker.WorkerSupportsCancellation = True 
    AddHandler (worker.DoWork), AddressOf begin_upload 

    'call this and move on? 
    worker.RunWorkerAsync() 

    lblmsg.Text = "Successfully initiated upload" 

End Sub 

Sub begin_upload(s As Object, e As DoWorkEventArgs) 

    Dim request As New YouTubeRequest(settings) 
    Dim vidupload As New Video() 

    vidupload.Title = "My Big Test Movie" 
    vidupload.Tags.Add(New MediaCategory("Nonprofit", YouTubeNameTable.CategorySchema)) 
    vidupload.Keywords = "church, jesus" 
    vidupload.Description = "See the entire video" 
    vidupload.YouTubeEntry.Private = False 
    vidupload.YouTubeEntry.setYouTubeExtension("location", "Downers Grove, IL") 
    vidupload.YouTubeEntry.MediaSource = New MediaFileSource("c:\users\greg\test3.asf", "video/x-ms-wmv") 

    Dim createdVideo As Video = Request.Upload(vidupload) 
End Sub 

Answer 1

你可能想看看進入Task Parallel Library添加多線程代碼。既然你提供的代碼：

添加此import語句

Imports System.Threading.Tasks 

而這個簡單的語句來替換所有BackgroundWorker的邏輯：

Dim uploadTask As Task = Task.Factory.StartNew(Sub() 
                 Dim request As New YouTubeRequest(settings) 
                 Dim vidupload As New Video() 

                 vidupload.Title = "My Big Test Movie" 
                 vidupload.Tags.Add(New MediaCategory("Nonprofit", YouTubeNameTable.CategorySchema)) 
                 vidupload.Keywords = "church, jesus" 
                 vidupload.Description = "See the entire video" 
                 vidupload.YouTubeEntry.Private = False 
                 vidupload.YouTubeEntry.setYouTubeExtension("location", "Downers Grove, IL") 
                 vidupload.YouTubeEntry.MediaSource = New MediaFileSource("c:\users\greg\test3.asf", "video/x-ms-wmv") 

                 Dim createdVideo As Video = request.Upload(vidupload) 
                End Sub) 

現在你有uploadTask上傳視頻的背景並且您的UI線程將可以自由處理其他代碼。如果你想要取消和進度報告，它會變得更加複雜，但是頂部的鏈接應該讓你開始。