如何在进度条完成时触发事件

本文关键字：完成时 事件 | 更新日期: 2023-09-27 18:09:02

我创建了一个Windows窗体程序，它可以分解文件并将其组件发送到服务器。这些文件很大，所以我创建了一个progressBar，这样用户就不会认为它在事务发生时冻结了。我想做的是有一些机制，将主动触发只有当所有线程完成而不阻塞UI线程(再次，所以平民不会认为它冻结)。我能想到的最好的办法是一种被动的"等到事情发生"，但我觉得必须有更好的方法来做到这一点。我尝试过创建事件或回调，但老实说，我比开始时更困惑。下面是我现在如何做这件事的一个例子:

    public partial class Program : Form
    {
        private readonly OpenFileDialog _ofd = new OpenFileDialog();
        public delegate void BarDelegate();
        private string _path;
        private void button1_Click(object sender, EventArgs e)
        {
            if (_ofd.ShowDialog() != DialogResult.OK) return;
            textBox1.Text = _ofd.SafeFileName;
            _path = _ofd.FileName;
        }
        private void button2_Click(object sender, EventArgs e)
        {
            var allLinesFromFile = File.ReadAllLines(_path);
            progressBar1.Minimum = 0;
            progressBar1.Maximum = allLinesFromFile.Length;
            Task.Factory.StartNew(() => Parallel.ForEach(allLinesFromFile, DoSomething));
            while (progressBar1.Value < progressBar1.Maximum) //there has to be a better way to do this...
            {
                MessageBox.Show("Please wait.", "Record Poster", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
            }
            //some processes here which should only take place after all threads are complete.
            var postingComplete = MessageBox.Show("The posting is complete!", "Record Poster", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
            if (postingComplete == DialogResult.OK) Environment.Exit(0);
        }
        private void DoSomething(string record)
        {
            //some string manipulation and server transactions here
            BeginInvoke(new BarDelegate(() => progressBar1.Increment(1)));
        }
    }

如何在进度条完成时触发事件

尝试使用微软的响应式框架(NuGet "System.Reactive.Windows.Forms")。然后你的代码变成:

    private void button2_Click(object sender, EventArgs e)
    {
        var allLinesFromFile = File.ReadAllLines(_path);
        progressBar1.Minimum = 0;
        progressBar1.Maximum = allLinesFromFile.Length;
        IDisposable subscription =
            allLinesFromFile
                .ToObservable()
                .SelectMany(f => Observable.Start(() => DoSomething(f)))
                .ObserveOn(this)
                .Do(x => progressBar1.Value += 1)
                .Subscribe(x => { }, () =>
                {
                    var postingComplete = MessageBox.Show("The posting is complete!", "Record Poster", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
                    if (postingComplete == DialogResult.OK)
                    {
                        Application.Exit();
                    }
                });
    }
    private void DoSomething(string record)
    {
        System.Threading.Thread.Sleep(5);
    }

如果你想早点停止，那就打电话给subscription.Dispose()。

你应该使用BackGroundWorker类，参见:如何使用BackGroundWorker ?

和使用BackGroundWorker.RunWorkerComplete时，线程已经完成

后台worker:

 **Backgroundworker (System.ComponentModel)**
 BackgroundWorker loader = new BackgroundWorker();
    loader.DoWork += load_Specials_BW_Thread;
        loader.WorkerReportsProgress = true;
        loader.ProgressChanged += load_Special_Feeds_Progress_Changed;
    private void load_Specials_BW_Thread(object sender, DoWorkEventArgs e)
    {
        int pctComplete = (int)Math.Floor(ptComplete * 100);//recs done / total recs
        (sender as BackgroundWorker).ReportProgress(pctComplete);
    }

祝你好运!

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