async/await 的引用

static async void Start()
{
string s = "ass";

Console.WriteLine(getMemory(s)+"Hello World!" + Thread.CurrentThread.ManagedThreadId);

await AsyncMethod();
Console.WriteLine(getMemory(s) + "End World!" + Thread.CurrentThread.ManagedThreadId);
Console.WriteLine();
}
static async Task AsyncMethod()
{

await Task.Run(() =>
{
Console.WriteLine("AsyncMethod 执行," + Thread.CurrentThread.ManagedThreadId);
});
}

public static string getMemory(object o) // 获取引用类型的内存地址方法 
{
　　GCHandle h = GCHandle.Alloc(o, GCHandleType.WeakTrackResurrection);

　　IntPtr addr = GCHandle.ToIntPtr(h);

　　return "0x" + addr.ToString("X");
}

红色的变量的 地址在await  两边一样吗？

是不一样的！

 getMemory 这个方法换个写法就一样了：

 public static string getMemory(object o) // 获取引用类型的内存地址方法 
        {
            GCHandle h = GCHandle.Alloc(o, GCHandleType.Pinned);

            IntPtr addr = h.AddrOfPinnedObject();
           
            return "0x" + addr.ToString("X");
        }

 这个值应该是一个的。至少地址是一个。因为引用类型都是在堆上。堆是进程所有的。

async 和await 是成对出现的。有一个注意的点：async 是方法的修饰符，这个方法的await 之后的是回调。出了这个方法就不是的了。

在Winform 程序的Buttion_Click() 方法中，使用了这种异步语法，是没问题的，

     private async void button1_Click(object sender, EventArgs e)
        {
            textBox1.Text += "zzz " + Thread.CurrentThread.ManagedThreadId.ToString() + "
";
            await Task.Run(() => { Thread.Sleep(2000); });
            button1.Text += "2";
            MessageBox.Show("))))))))))))))))s");

            textBox1.Text += "ttt " + Thread.CurrentThread.ManagedThreadId.ToString()+"
";

        }

　　

这个Buttion_Click 上可以写async!   Await 后面的代码，是主线程操作了控件，这是编译器知道这个程序，然后进行了相应的处理。

async 这种语法，在Web项目中，会增加吞吐量，不会缩短对单个请求的响应时间。

下面是一个测试：

 public static async void Test()
        {
           var t1= Task.Run(() => {
                Thread.Sleep(2000);
                Console.WriteLine("Sleep over");
            });

             t1.Wait();
            Console.WriteLine("Sleep over....1");

            var t2 = Task.Run(() => {

                Thread.Sleep(2000);
                Console.WriteLine("Sleep over 2");
            });

            t2.Wait();
            Console.WriteLine("Sleep over.....2");
        }

        public static  void Main(string[] args)
        {
            Console.WriteLine("start..");
            Test();
            Console.WriteLine("over");
            Console.ReadLine();
        }

start..
Sleep over
Sleep over....1
Sleep over 2
Sleep over.....2
over

Wait(); 换成 awiat t
打印如下：

start..
over
Sleep over
Sleep over....1
Sleep over 2
Sleep over.....2

下面是一个Async 的解析后的治理：

  static async Task Main()
        {
            Console.WriteLine("111111111111111");
            await Task.Run(() => {
                Console.WriteLine("2222222222222");
            });
            Console.WriteLine("33333");
        }

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;

public class button1_Click : IAsyncStateMachine
{
    public int state1;

    public AsyncVoidMethodBuilder t__builder;

    public object sender;

    public EventArgs e;



    private TaskAwaiter taskWaiter;

    private void MoveNext()
    {
        int num = state1;
        try
        {
            TaskAwaiter awaiter;
            if (num != 0)
            {
                Console.WriteLine("111111111111111");
                awaiter = Task.Run(delegate
                {
                    Console.WriteLine("2222222222222");
                }).GetAwaiter();
                if (!awaiter.IsCompleted)
                {
                    num = (state1 = 0);
                    taskWaiter = awaiter;
                    button1_Click stateMachine = this;
                    t__builder.AwaitUnsafeOnCompleted(ref awaiter, ref stateMachine);
                    return;
                }
            }
            else
            {
                awaiter = taskWaiter;
                taskWaiter = default(TaskAwaiter);
                num = (state1 = -1);
            }
            awaiter.GetResult();
            Console.WriteLine("33333");
        }
        catch (Exception exception)
        {
            state1 = -2;
            t__builder.SetException(exception);
            return;
        }
        state1 = -2;
        t__builder.SetResult();
    }

    void IAsyncStateMachine.MoveNext()
    {
        //ILSpy generated this explicit interface implementation from .override directive in MoveNext
        this.MoveNext();
    }


    private void SetStateMachine(IAsyncStateMachine stateMachine)
    {
    }

    void IAsyncStateMachine.SetStateMachine(IAsyncStateMachine stateMachine)
    {
        //ILSpy generated this explicit interface implementation from .override directive in SetStateMachine
        this.SetStateMachine(stateMachine);
    }
}