js异步改同步

深碍√TFBOYSˉ_ 2022-12-04 01:04 331阅读 0赞

异步同步执行

promise是什么？  
1、主要用于异步计算  
2、可以将异步操作队列化，按照期望的顺序执行，返回符合预期的结果  
3、可以在对象之间传递和操作promise，帮助我们处理队列

/* prmoise链式写法 */
     			//prmoise链式写法 调用
                this.GetSafeTaskStateNum().then(res=>{
                    console.log("aaa",res)
                    return res
                }).then((res2)=>{
                    console.log("aaa222",res2)
                    this.GetSafeUnitTaskList(res2);
                })
    
    
            /* 
            
                GetSafeTaskStateNum(){
                    return new Promise((resolve,reject)=>{
                            this.$axios.get(this.$api.GetSafeTaskStateNum,{params:this.page}).then(res=>{
                            console.log("我要讓裝藥状态先获取到",res);
                            // this.screenBtns[0].num = res.result[0].value
                            // this.screenBtns[1].num = res.result[1].value
                            resolve(res)
                        })
                    }) 
                },
                GetSafeUnitTaskList(res2){
                
                    this.$axios.get(this.$api.GetSafeUnitTaskList,{params:this.page}).then(res=>{
                        console.log("等状态完成了才能执行",res2);
                        ({items: this.tableData,totalCount: this.page.total} = res.result);
                    })
                },
            */
    
    
           
    
           /* Async操作 */
           //Async操作调用
            // this.GetSafeUnitTaskList();
            
            /* GetSafeTaskStateNum(){ 
                return Promise.resolve( 
                    this.$axios.get(this.$api.GetSafeTaskStateNum,{params:this.page}).then(res=>{
                        console.log("我要讓裝藥状态先获取到",res);
                        return res
                    })
                )
            },
            
            async GetSafeUnitTaskList(){
                    const v1 = await this.GetSafeTaskStateNum();
                     console.log("等状态完成了才能执行v1",v1);
                    this.$axios.get(this.$api.GetSafeUnitTaskList,{params:this.page}).then(res=>{
                       
                        ({items: this.tableData,totalCount: this.page.total} = res.result);
                    })
                }, */

详细：

[promise和async await区别在哪？到底怎么用？][promise_async await]  
[理解 JavaScript 的 async/await][JavaScript _ async_await]  
[ES6关于Promise的用法][ES6_Promise]  
[Promise和Async/Await用法整理][Promise_Async_Await]  
[Async视频讲解][Async]  
[async,await视频讲解][async_await]  
[关于async/await、promise和setTimeout执行顺序][async_await_promise_setTimeout]

[promise_async await]: https://blog.csdn.net/weixin_46176363/article/details/110819350
[JavaScript _ async_await]: https://segmentfault.com/a/1190000007535316
[ES6_Promise]: https://segmentfault.com/a/1190000011652907
[Promise_Async_Await]: https://www.jianshu.com/p/fe0159f8beb4
[Async]: https://www.bilibili.com/video/BV1sZ4y1N7WG
[async_await]: https://www.bilibili.com/video/BV1GA411Y76B
[async_await_promise_setTimeout]: https://blog.csdn.net/yun_hou/article/details/88697954