实现跨线程访问UI控件的3种方法

namespace 多线程
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }  

        private void Form2_Load(object sender, EventArgs e)
        {
            //1.New 一个thread.
            //给新创建的thread绑一个带参的方法ParameterizedThreadStart
            new Thread((ParameterizedThreadStart)(Dosomething)).Start();
            //如果绑的是无参的方法，就用ThreadStart
            //new Thread((ThreadStart)(Dosomething)).Start();  

            //2.在线程池里面做.
            ThreadPool.QueueUserWorkItem(new WaitCallback(Dosomething));  

            //3.用backgroundworker
            using (BackgroundWorker bw = new BackgroundWorker())
            {
                bw.DoWork += new DoWorkEventHandler(bw_DoWork);
                bw.RunWorkerAsync();
            }
        }  

        private void bw_DoWork(object sender, DoWorkEventArgs e)
        {
            Dosomething("");
        }  

        private void Dosomething(object o)
        {
            var text = "跨线程设值";
            UpdateTextboxText(text);
        }  

        private void UpdateTextboxText(string text)
        {
            if (this.InvokeRequired)
            {
                //this.Invoke((EventHandler)(SetText),new object[] {text});
                //this.Invoke((MethodInvoker)(delegate { textBox1.Text = text; }));
                this.Invoke((Action)( delegate {UpdateTextboxText(text);}));
                //其中Action,MethodInvoker,Func<>,EventHandler都是系统定义好的委托类型
            }
            else
            {
                textBox1.Text = text;
            }
        }
    }
}