ObjectDisposeException - 在 GUI 线程中运行秒表

Question

我有一个在不同线程中运行的秒表，它更新标签中的 GUI 线程以随着时间的推移而显示。当我的程序关闭时，当我在 Form GUI 中调用 this.Invoke(mydelegate); 以使用秒表中的时间更新标签时，它会抛出 ObjectDisposeException 。

我如何摆脱这个ObjectDisposeException？

我试图在 FormClosing 事件中停止秒表，但它无法处理它。

这是代码：

System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
            stopwatch = sw;

            sw.Start();
            //System.Threading.Thread.Sleep(100);
            System.Threading.Thread t = new System.Threading.Thread(delegate()
            {
                while (true)
                {
                TimeSpan ts = sw.Elapsed;

                string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}.{3:00}",
                ts.Hours, ts.Minutes, ts.Seconds,
                ts.Milliseconds / 10);

                timeElapse = elapsedTime;

                  UpdateLabel();
                }
            });
            stopwatchThread = t;
            t.Start();

 public void UpdateLabel()
        {
            db = new doupdate(DoUpdateLabel);

            this.Invoke(db);
        }

 public void DoUpdateLabel()
        {
            toolStripStatusLabel1.Text = timeElapse;
        }

Answer 1

看起来是当您关闭应用程序时秒表正在被释放，但线程仍在运行并尝试使用它。您可以在关闭应用程序之前（在 FormClosing 事件中）先停止线程吗？

Answer 2

相同的代码，现在使用BackgroundWorker和有序关闭，确保在后台线程首先停止运行之前表单不会关闭：

using System;
using System.Threading;
using System.Windows.Forms;
using System.Diagnostics;

namespace WindowsFormsApplication1 {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
            backgroundWorker1.DoWork += backgroundWorker1_DoWork;
            backgroundWorker1.ProgressChanged += backgroundWorker1_ProgressChanged;
            backgroundWorker1.RunWorkerCompleted += backgroundWorker1_RunWorkerCompleted;
            backgroundWorker1.WorkerReportsProgress = backgroundWorker1.WorkerSupportsCancellation = true;
            backgroundWorker1.RunWorkerAsync();
        }
        bool mCancel;
        void backgroundWorker1_RunWorkerCompleted(object sender, System.ComponentModel.RunWorkerCompletedEventArgs e) {
            if (e.Error != null) MessageBox.Show(e.Error.ToString());
            if (mCancel) this.Close();
        }
        protected override void OnFormClosing(FormClosingEventArgs e) {
            if (backgroundWorker1.IsBusy) mCancel = e.Cancel = true;
            backgroundWorker1.CancelAsync();
        }
        void backgroundWorker1_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e) {
            label1.Text = e.UserState as string;
        }
        void backgroundWorker1_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e) {
            Stopwatch sw = Stopwatch.StartNew();
            while (!backgroundWorker1.CancellationPending) {
                TimeSpan ts = sw.Elapsed;
                string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}.{3:00}",
                    ts.Hours, ts.Minutes, ts.Seconds, ts.Milliseconds / 10);
                backgroundWorker1.ReportProgress(0, elapsedTime);
                Thread.Sleep(15);
            }
        }
    }
}

请注意，需要Sleep()调用，不可能将调用编组到UI线程每秒超过约1000次。