C# 应用程序在检索 youtube 请求时卡住

Question

我正在从 YouTube 检索 200 个视频 URL。但是它卡住了我的应用程序，我怎样才能使它工作，我也在后台工作人员中使用它，但仍然无法工作。

在此我使用了后台工作人员，我想在 listBox2 中添加视频标题。

初始化 worker ..

    worker1 = new BackgroundWorker();

    worker1.DoWork += new DoWorkEventHandler(worker1_DoWork);
    worker1.ProgressChanged += new ProgressChangedEventHandler(worker1_ProgressChanged);
    worker1.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker1_RunWorkerCompleted);

    worker1.WorkerReportsProgress = true;   
worker1.WorkerSupportsCancellation = true;

    int ii = 0;
    int jj = 0;

做功函数。

void worker1_DoWork(object sender, DoWorkEventArgs e)
    {
        int progressVal = 0;
        textBox1.Invoke(new Action(
                            delegate()
                            {

                                if (worker1.CancellationPending)
                                { return; }

                                    string[] videoLink = textBox1.Text.Split(new char[] { '\n' });
                                    progressBar1.Maximum = videoLink.Length ;

                                    foreach (string s in videoLink)
                                    {
                                        string videoID;

                                        try
                                        {
                                            videoID = s.Split(new char[] { '=' })[1].Trim();
                                        }
                                        catch (Exception ex)
                                        {
                                            MessageBox.Show(this, "Please enter correct video links\nExample : http://www.youtube.com/watch?v=123456789", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                                            return;
                                        }

                                        YouTubeRequestSettings reqSettings = new YouTubeRequestSettings("Youtube Comments", devkey, usernames[jj], password) { Timeout = -1 };
                                        YouTubeRequest request = new YouTubeRequest(reqSettings);

                                        jj++;
                                        if (jj == usernames.Length) jj = 0;

                                        string commentContent = listBox1.Items[ii].ToString();
                                        ii++;
                                        if (ii == listBox1.Items.Count) ii = 0;

                                        Comment comment = new Comment();
                                        comment.Content = commentContent;

                                        try
                                        {
                                            Video video = request.Retrieve<Video>(new Uri("http://gdata.youtube.com/feeds/api/videos/" + videoID));
                                            worker1.ReportProgress(progressVal++, "[" + comment.Content + "] Added to : " + "VideoTitle");

                                            //    request.AddComment(request.Retrieve<Video>(new Uri("http://gdata.youtube.com/feeds/api/videos/" + videoID)), comment);
                                        }
                                        catch (Exception ex)
                                        {
                                            worker1.ReportProgress(progressVal++, "Error Accoured : " + "VideoTitle");
                                        }
                                    }


                            }));


    }

我希望它每次在列表框中添加标题时都能取得进展，但它只在最后显示进度。完成整个过程后。

void worker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        progressBar1.Value = progressBar1.Maximum;
        this.Show();
    }

    void worker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
        progressBar1.Value = e.ProgressPercentage;
        listBox2.Items.Add(e.UserState.ToString());

    }

Answer 1

将列表框刷新命令添加到您的进度更改中。

void worker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    progressBar1.Value = e.ProgressPercentage;
    listBox2.Items.Add(e.UserState.ToString());
    listbox2.Items.Refresh();
}

你也可以实现 INotifyPropertyChanged在您的绑定(bind)上(如果您正在使用 WPF)。