Promise用法

hechengjin

1. 'use strict'
   
2. 
   
3. let Deferred = function () {
   
4.   this.promise = new Promise((resolve, reject) => {
   
5.     this.resolve = resolve
   
6.     this.reject = reject
   
7.   })
   
8. 
   
9.   this.promise.canceled = false
   
10.   this.promise.cancelers = []
    
11.   this.promise.cancel = () => {
    
12.     this.promise.canceled = true
    
13.     for (let canceler of this.promise.cancelers) {
    
14.       try {
    
15.         canceler()
    
16.       } catch (e) {
    
17.         console.log(e + e.stack)
    
18.       }
    
19.     }
    
20.   }
    
21.   this.then = this.promise.then.bind(this.promise)
    
22.   this.catch = this.promise.catch.bind(this.promise)
    
23. }
    
24. 
    
25. exports.defer = () => new Deferred()
    

复制代码

第一次查询

let loadListDeferred = defer()
执行查询
loadListDeferred.then(() => {
    查询结果清除  ----这里在执行第二次查询时才会执行到
  })


第二次查询
if (oadListDeferred) {
   loadListDeferred.resolve()   ----触发上面的then操作
  }

hechengjin

let loadDeferred = defer()
let finished = false

  spawn(function * () {
    while (true) {
      console.log('777777777777777')
      // yield WinJS.Promise.any([sleep(1000), loadDeferred])
      yield sleep(1000)
      loadDeferred.then(() => {
        finished = true
      })
      if (finished) {
        break
      }
    }
  })

  top.tryCloseWindow = DoCommandClose.bind(top)

function DoCommandClose () {
  let ret = false
  loadDeferred.resolve()
  console.log('=======================')
  top.close()
  return ret
}