C#中异步和多线程的区别介绍

delegate void AsyncFoo(int i);

static void Main(string[] args)
{
    PrintCurrThreadInfo("Main()");
    for (int i = 0; i < 10; i++)
    {
        PostAsync();
    }
    Console.ReadLine();
}
///<summary>
/// 输出当前线程的信息
///</summary>
///<param name="name">方法名称</param>

static void PrintCurrThreadInfo(string name)
{
    Console.WriteLine("Thread Id of " + name + " is: " + Thread.CurrentThread.ManagedThreadId + ", current thread is "
             + (Thread.CurrentThread.IsThreadPoolThread ? "" : "not ")
             + "thread pool thread.");
}


///<summary>
/// 投递一个异步调用
///</summary>
static void PostAsync()
{
    AsyncFoo caller = new AsyncFoo(Foo);
    caller.BeginInvoke(1000, new AsyncCallback(FooCallBack), caller);
}

///<summary>
/// 测试方法，Sleep一定时间
///</summary>
///<param name="i">Sleep的时间</param>
static void Foo(int i)
{
    PrintCurrThreadInfo("Foo()");
    Thread.Sleep(i);
}

static void FooCallBack(IAsyncResult ar)
{
    PrintCurrThreadInfo("FooCallBack()");
    AsyncFoo caller = (AsyncFoo)ar.AsyncState;
    caller.EndInvoke(ar);
}

Thread Id of Main() is: 1, current thread is not thread pool thread.
Thread Id of Foo() is: 3, current thread is thread pool thread.
Thread Id of FooCallBack() is: 3, current thread is thread pool thread.
Thread Id of Foo() is: 3, current thread is thread pool thread.
Thread Id of Foo() is: 4, current thread is thread pool thread.
Thread Id of Foo() is: 5, current thread is thread pool thread.
Thread Id of FooCallBack() is: 3, current thread is thread pool thread.
Thread Id of Foo() is: 3, current thread is thread pool thread.
Thread Id of FooCallBack() is: 4, current thread is thread pool thread.
Thread Id of Foo() is: 4, current thread is thread pool thread.
Thread Id of Foo() is: 6, current thread is thread pool thread.
Thread Id of FooCallBack() is: 5, current thread is thread pool thread.
Thread Id of Foo() is: 5, current thread is thread pool thread.
Thread Id of Foo() is: 7, current thread is thread pool thread.
Thread Id of FooCallBack() is: 3, current thread is thread pool thread.
Thread Id of Foo() is: 3, current thread is thread pool thread.
Thread Id of FooCallBack() is: 4, current thread is thread pool thread.
Thread Id of FooCallBack() is: 6, current thread is thread pool thread.
Thread Id of FooCallBack() is: 5, current thread is thread pool thread.
Thread Id of FooCallBack() is: 7, current thread is thread pool thread.
Thread Id of FooCallBack() is: 3, current thread is thread pool thread.