Question

如何在提供的代码中循环停止？哪些代码应处于“ STOP”状态才能在循环时停止？

当侦听器赋予 while 另一个状态时，循环仍在运行。 常量状态值保持“开始”。侦听器赋予新状态后，它不会改变。

constructor(){
    events.on("imdb-scraper-engine", ({status}) =>{
        this.scraper(status);
    });
    this.scraper('INIT');
}

async scraper(status){

while(status == 'START'){
    await axios.get('https://jsonplaceholder.typicode.com/posts').then((result)=>{
        console.log(result);
    });

}

    if((status == 'STOP')){console.log('Process was stopped');}
    if((status == 'INIT')){console.log('Engine Initialized')}

}

- eidt发现我总是开始在构造函数中调用this.scraper的新进程。但是仍然想知道如何在while循环中停止。

Answer 1

Try it: 


     constructor(){
            events.on("imdb-scraper-engine", ({status}) =>{
                this.scraper(status);
            });
            this.scraper('INIT');
        }

        async scraper(status){
        console.log(status)
        while(status == 'START' && status != 'STOP'){
console.log(status)
            await axios.get('https://jsonplaceholder.typicode.com/posts').then((result)=>{
                console.log(result);
            });

        }

            if((status == 'STOP')){console.log('Process was stopped');}
            if((status == 'INIT')){console.log('Engine Initialized')}

        }

Answer 2

根据您可能要实现的目标，我可以为您设计一个想法。

这可能无法正常工作。

theLoop; //its a variable

constructor(){
    this.listenEvent();
    this.scraper('INIT');
}
function listenEvent(){
  events.on("imdb-scraper-engine", ({status}) =>{
         if(status=='STOP'){
            clearTimeout(this.theLoop);
         }
         this.scrapper(status);
    });
}
function startWhileLoop() {
   this.theLoop = setTimeout(async function(){ 
       await axios.get('https://jsonplaceholder.typicode.com/posts').then((result)=>{
       console.log(result);
     });
   }, 0);
}

scraper(status){
   while(status == 'START'){
     startWhileLoop();
   }
   if((status == 'STOP')){console.log('Process was stopped');}
   if((status == 'INIT')){console.log('Engine Initialized')}
}

在while循环NODEJS

2 个答案: