C#使用线程操作控件

C#使用线程操作控件

1.不用线程

 private void button1_Click(object sender, EventArgs e)
        {
            for (int i = 0; i < 100000; i++)
            {
                listBox1.Items.Add(i.ToString());
            }
        }

这种方法，界面会卡死

2.使用backgrounder背景线程

  private void button1_Click(object sender, EventArgs e)
        {
            BackgroundWorker bw = new BackgroundWorker();
            bw.ProgressChanged += Bw_ProgressChanged;
            bw.DoWork += Bw_DoWork;
            bw.RunWorkerCompleted += Bw_RunWorkerCompleted;
            bw.WorkerReportsProgress = true;
            bw.RunWorkerAsync();

        }

        private void Bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            listBox1.Items.Add("done");
        }

        private void Bw_DoWork(object sender, DoWorkEventArgs e)
        {
            BackgroundWorker worker = sender as BackgroundWorker;

            for (int i = 1; i <= 1000000; i++)
            {
                if (worker.CancellationPending == true)
                {
                    e.Cancel = true;
                    break;
                }
                else
                {
                    
                   System.Threading.Thread.Sleep(100);
                   worker.ReportProgress(i );
                }
            }
        }

        private void Bw_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            listBox1.Items.Add(e.ProgressPercentage.ToString());
        }

3.使用Thread线程

 private void button2_Click(object sender, EventArgs e)
        {
            ThreadStart threadStart = new ThreadStart(run);
            Thread thread = new Thread(threadStart);
            thread.Start();

            //Thread thread = new Thread(run);
            //thread.Start();
        }

        public void run()
        {
            for (int i = 1; i <= 1000000; i++)
            {
                listBox1.Invoke(new Action(() => {
                    listBox1.Items.Add(i);
                }));
            
            
            }
        }

4.使用Task

  private void button4_Click(object sender, EventArgs e)
        {
            Task.Run(() =>
            {
                for (int i = 0; i < 1000000; i++)
                {
                    listBox1.Invoke(new Action(() => { listBox1.Items.Add(i); }));
                }
            });
        }

5.委托（比较规范的写法）

public delegate void SetTextHandler(string result);
        Thread thread;
        private void button5_Click(object sender, EventArgs e)
        {
            thread = new Thread(new ThreadStart(PrintEven));
            thread.Start();
        }
        private void PrintEven()
        {
            for (int i = 0; i < 10000; i++)
            {
                setItem(i.ToString());
            }
        }

        private void setItem(string result)
        {
            if (listBox1.InvokeRequired == true)
            {
                SetTextHandler setTextHandler = new SetTextHandler(setItem);
                listBox1.Invoke(setTextHandler, new object[] { result });

            }
            else
            {

                listBox1.Items.Add(result);
               
            }

        }

6.取消跨线程检查

下面这种方法报错：程间操作无效: 从不是创建控件“listBox1”的线程访问它。”

 private void button6_Click(object sender, EventArgs e)
        {
         Thread thread = new Thread(new ThreadStart(run2));
            thread.Start();
        }
        public void run2()
        {
            for (int i = 0; i < 100000; i++)
            {
                listBox1.Items.Add(i.ToString());
            }
        }

解决方法：

   public Form7()
        {
            InitializeComponent();
            Control.CheckForIllegalCrossThreadCalls = false;//取消跨线程检查，这种方法不推荐
        }