delegate void DoWork();private void button1_Click(object sender, EventArgs e){//辅助方法,查看当前线程Debug.WriteLine(string.Format("Window Form Method.Thread ID:#{0}",Thread.CurrentThread.ManagedThreadId));//Label lblStatus 属于主线程的控件[1]this.lblStatus.Text = "Asynchronous Start.";//使用委托来调用异步方法DoWork work = DoWorkMethod;work.BeginInvoke(OnWorkCallback, work);}void OnWorkCallback(IAsyncResult asyncResult){//辅助方法,查看当前线程Debug.WriteLine(string.Format("Asynchronous Callback Method.Thread ID:#{0}",Thread.CurrentThread.ManagedThreadId));DoWork work = asyncResult.AsyncState as DoWork;if (work != null){work.EndInvoke(asyncResult);}// 报错:"线程间操作无效: 从不是创建控件“lblStatus”的线程访问它."this.lblStatus.Text = "Asynchronous End"; //上面注释[1]
 　　　　}void DoWorkMethod(){Thread.Sleep(3000);//模拟耗时工作}

delegate void DoWork();private void button1_Click(object sender, EventArgs e){//更新状态,添加到Listbox 中AddValue("Asynchronous Start.");//使用委托来调用异步方法DoWork work = DoWorkMethod;work.BeginInvoke(OnWorkCallback, work);}void OnWorkCallback(IAsyncResult asyncResult){DoWork work = asyncResult.AsyncState as DoWork;if (work != null){work.EndInvoke(asyncResult);}//(1)方法:调用Control控件的Invoke//Action<string> asyncUpdateState = UpdateStatus; //Action<string> 介绍=> 附1//Invoke(asyncUpdateState, "1:Asynchronous End.");//(2)方法:直接在异步调用的线程下UpdateStatus("2:Asynchronous End.");}void UpdateStatus(string input){//把你需要通知的控件Control 赋值给ISynchronizeInvoke//来实现线程间的通信ISynchronizeInvoke async = this.listBoxStatus;//使用(1)方法,InvokeRequired == false ,来源当前(Window Form)主线程if (async.InvokeRequired == false)AddValue(input);else// 使用(2)方法 == true ,来源其他线程(异步)
 　　　　　　{　Action<string> action = new Action<string>(status =>{AddValue(status);});//调用ISynchronizeInvoke 提供的Invoke 同步方法,阻碍线程,直到调用结束//也可以使用ISynchronizeInvoke 提供的异步BeginInvoke/EndInvoke方法来实现调用.async.Invoke(action, new object[] { input });}}void AddValue(string input){this.listBoxStatus.Items.Add(string.Format("[(#{2}){0}]Context is null:{1}", input,Thread.CurrentContext==null, Thread.CurrentThread.ManagedThreadId));}void DoWorkMethod(){Thread.Sleep(3000);//模拟耗时工作}

static class Program{static void Main(){//1,在Main 主线程中运行,查看线程ID和同步上下文Console.WriteLine("0.ThreadID:#{1},Synchronization Context is null?{0}",SynchronizationContext.Current == null, Thread.CurrentThread.ManagedThreadId);//2,在Main 主线程中运行,实例化空对象Test,查看线程ID和同步上下文Test a = new Test();Console.WriteLine("1.ThreadID:#{1},Synchronization Context is null?{0}",SynchronizationContext.Current == null, Thread.CurrentThread.ManagedThreadId);//3,在Main 主线程中运行,实例化FormTest对象(继承Form),查看线程ID和同步上下文FormTest test = new FormTest();Console.WriteLine("2.ThreadID:#{1},Synchronization Context is null?{0}",SynchronizationContext.Current == null, Thread.CurrentThread.ManagedThreadId);//4,在新线程中运行,查看线程ID和同步上下文new Thread(work).Start();Console.Read();}static void work(){Console.WriteLine("3.ThreadID:#{1},Synchronization Context is null?{0}",SynchronizationContext.Current == null, Thread.CurrentThread.ManagedThreadId);}}public class FormTest : System.Windows.Forms.Form { }public class Test { }

public virtual void Post(SendOrPostCallback d, object state){ThreadPool.QueueUserWorkItem(new WaitCallback(d.Invoke), state);}public virtual void Send(SendOrPostCallback d, object state){d(state);}

delegate void DoWork();private void button1_Click(object sender, EventArgs e){//System.Windows.Forms.Form 自动的创建默认的同步上下文对象,//直接的获取当前的同步上下文对象SynchronizationContext context = SynchronizationContext.Current;//更新状态,添加到Listbox 中AddValue<string>("Asynchronous Start.");//使用委托来调用异步方法DoWork work = DoWorkMethod;work.BeginInvoke(OnWorkCallback, context);}void OnWorkCallback(IAsyncResult asyncResult){AsyncResult async = (AsyncResult)asyncResult;DoWork work = (DoWork)async.AsyncDelegate;work.EndInvoke(asyncResult);//更新状态UpdateStatus("Asynchronous End.", asyncResult.AsyncState);}void UpdateStatus(object input,object syncContext){//获取主线程(Window Form)中同步上下文对象SynchronizationContext context = syncContext as SynchronizationContext;//使用SynchronizationContext 类中异步Post 方法SendOrPostCallback callback = new SendOrPostCallback(p => {AddValue<object>(p);});context.Post(callback, input);//Post 为异步,Send 为同步
 }void AddValue<T>(T input){this.listBoxStatus.Items.Add(string.Format("[(#{2}){0}]Context is null:{1}", input, Thread.CurrentContext == null, Thread.CurrentThread.ManagedThreadId));}void DoWorkMethod(){Thread.Sleep(3000);//模拟耗时工作}

static class Program{static void Main(){Output("Main Thread Start.");//为主线程创建Synchronization Contextvar context = new SynchronizationContext();//开始一个新线程Thread threadB = new Thread(work);threadB.Start(context);Console.Read();}static void work(object context){Output("Thread B");//获取主线程中的同步上下文对象SynchronizationContext sc = context as SynchronizationContext;//异步的方式和主线程通信,并发送"Hello World".sc.Post(new SendOrPostCallback(p =>{Output(p);}), "Hello World");}static void Output(object value){Console.WriteLine("[ThreadID:#{0}]{1}", Thread.CurrentThread.ManagedThreadId, value);}}

public class MySynchronizedClass{private AsyncOperation operation;public event EventHandler somethingHappened;public MySynchronizedClass(){//创建AsyncOperation 对象,并把当前线程的同步上下文保持到AsyncOperation中.operation = AsyncOperationManager.CreateOperation(null);Thread workerThread = new Thread(new ThreadStart(DoWork));workerThread.Start();}private void DoWork(){SendOrPostCallback callback = new SendOrPostCallback(state =>{EventHandler handler = somethingHappened;if (handler != null){handler(this, EventArgs.Empty);}});operation.Post(callback, null);//注意1
 　　　　　　operation.OperationCompleted();}}