public class MyClass
{public MyClass(){DisplayValue(); //这里不会阻塞System.Diagnostics.Debug.WriteLine("MyClass() End.");}public Task<double> GetValueAsync(double num1, double num2){return Task.Run(() =>{for (int i = 0; i < 1000000; i++){num1 = num1 / num2;}return num1;});}public async void DisplayValue(){double result = await GetValueAsync(1234.5, 1.01);//此处会开新线程处理GetValueAsync任务，然后方法马上返回//这之后的所有代码都会被封装成委托，在GetValueAsync任务完成时调用System.Diagnostics.Debug.WriteLine("Value is : " + result);}
}

public void DisplayValue()
{System.Runtime.CompilerServices.TaskAwaiter<double> awaiter = GetValueAsync(1234.5, 1.01).GetAwaiter();awaiter.OnCompleted(() =>{double result = awaiter.GetResult();System.Diagnostics.Debug.WriteLine("Value is : " + result);});
} 

    public static class TaskAsyncHelper{/// <summary>/// 将一个方法function异步运行，在执行完毕时执行回调callback/// </summary>/// <param name="function">异步方法，该方法没有参数，返回类型必须是void</param>/// <param name="callback">异步方法执行完毕时执行的回调方法，该方法没有参数，返回类型必须是void</param>public static async void RunAsync(Action function, Action callback){Func<System.Threading.Tasks.Task> taskFunc = () =>{return System.Threading.Tasks.Task.Run(() =>{function();});};await taskFunc();if (callback != null)callback();}/// <summary>/// 将一个方法function异步运行，在执行完毕时执行回调callback/// </summary>/// <typeparam name="TResult">异步方法的返回类型</typeparam>/// <param name="function">异步方法，该方法没有参数，返回类型必须是TResult</param>/// <param name="callback">异步方法执行完毕时执行的回调方法，该方法参数为TResult，返回类型必须是void</param>public static async void RunAsync<TResult>(Func<TResult> function, Action<TResult> callback){Func<System.Threading.Tasks.Task<TResult>> taskFunc = ()=>{return System.Threading.Tasks.Task.Run(()=>{return function();});};TResult rlt = await taskFunc();if(callback != null)callback(rlt);}}