class AsyncTest{
//simple example
    async run(){
//按照顺序等待后输出
let one = await this.output("one", 1000);
console.log('output:'   one);
let two = await this.output("two", 3000);
console.log(two);
console.log('run.....');
}
//await and Promise.all difference
    async runDiff(){
let one = this.output('diff one', 2000);
let two = this.output('diff two', 2000);
console.log(  await two   await one );  //在2秒之后，两个都输出了，而不是各自都等待两秒
console.log('runDiff.....');
}
//Promise.all realize
    runAll(){
let nowTime = new Date();
console.log('b:'   nowTime.toTimeString());
let array = ["a", "b", "c"];
let that = this;
array.forEach(async function(item){
console.log( await that.output(item, 2000) );//2秒后同时输出
        });
let fn = async ()=>{
for(let item of array){
let v = await this.output(item, 2000);
console.log(v ); //分步骤两秒执行
            }
}
fn.call(this);
}
premosFn(){
let nowTime = new Date();
console.log('b:'   nowTime.toTimeString());
let array = ["a", "b", "c"];
let that = this;
//promise.all
let preFn = async function(){
let promises = array.map(function(item){
return that.output(item,2000); //同时开启多个定时器
            });
let r = await Promise.all(promises);
console.log(r.join(','));
}
preFn();
}
reject(){
let rejectFn = function(){
return new Promise((resolve, reject)=>{
setTimeout(()=>{
reject();
},2000);
});
}
let asyncReject = async function(){
try{
await rejectFn();
}catch( e) {
console.log('reject.....');
}
}
asyncReject();
}
output(log, time){
return new Promise(resolve=>{
setTimeout(()=>{
var nowTime = new Date();
resolve( nowTime.toTimeString()   ":"   log   "\r\n");
}, time);
});
}
}

public class AsyncDemo
{
private Task<string> Output(string val, int time)
{
return System.Threading.Tasks.Task.Run(() =>
{
System.Threading.Thread.Sleep(time * 1000);
return (DateTime.Now.ToLongTimeString())   ": "   val   "\r\n";
});
}
public async System.Threading.Tasks.Task Run()
{
string oneVal = await Output("One", 2);
string twoVal = await Output("Two", 2);
System.Console.WriteLine("Run \r\n"   oneVal   " "   twoVal);
}
public async System.Threading.Tasks.Task RunDiff()
{
Task<string> oneTask = Output("one", 2);
Task<string> twoTask = Output("two", 2);
string val = await oneTask   await twoTask;
System.Console.WriteLine("RunDiff \r\n"   val);
}
public async System.Threading.Tasks.Task RunAll()
{
System.Console.WriteLine("b:"   (DateTime.Now.ToLongTimeString()));
string[] array = new string[3] { "a", "b", "c" };
foreach(var item in array)
{
string v = await Output(item, 2);
System.Console.WriteLine(v);
}
}
public async System.Threading.Tasks.Task PromiseFn()
{
System.Console.WriteLine("b:"   (DateTime.Now.ToLongTimeString()));
string[] array = new string[3] { "a", "b", "c" };
List<System.Threading.Tasks.Task<string>> tasks = new List<System.Threading.Tasks.Task<string>>();
foreach (var item in array)
{
tasks.Add(Output(item, 2));
}
//waitAll返回值不能获取，他返回为void，而WhenAll则返回为一个Task（这个Task就有其列表值）
string[] r = await System.Threading.Tasks.Task.WhenAll(tasks.ToArray());
System.Console.WriteLine(string.Join(",",r));
}
public async System.Threading.Tasks.Task Reject()
{
Func<System.Threading.Tasks.Task> func = async () =>
{
throw new Exception("custom...");
await Output("reject", 2);
};
await func();
}
}

AsyncDemo asyncDemo = new AsyncDemo();
asyncDemo.Run().Wait();
asyncDemo.RunDiff().Wait();
asyncDemo.RunAll().Wait();
asyncDemo.PromiseFn().Wait();
try
{
asyncDemo.Reject().Wait();
}catch(Exception e)
{
System.Console.WriteLine("reject ex");
}

System.Console.WriteLine("b:"   (DateTime.Now.ToLongTimeString()));
string[] array = new string[3] { "a", "b", "c" };
var r = await this.Output(array.First(), 2).ContinueWith((tsc) =>
{
string v = tsc.GetAwaiter().GetResult();
return this.Output(v   "02", 2);
});
System.Console.WriteLine(r.Result);