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问题描述
描述:我在for循环中调用了HTTP请求.我想从服务文件中获取响应,然后增加循环.如何等待从服务文件中获取响应,然后执行循环. >
Description : I called an HTTP request inside for loop.I want to get the response from service file then increase loop.How can i wait to get response from service file then execute loop.
for(let i=0;i<final_arr.length;i++) { this.user.list_upload(JSON.stringify(ins_arr)).subscribe(data=>{ if(data.hasOwnProperty('STATUS')) { if(data.STATUS.toLowerCase()=='success') { this.update(); } else if(data.STATUS.toLowerCase() == 'error') { this.user.showToast(data.MESSAGE); } } },err=>{ this.user.showToast("Error occurred in service file"); }); }
请告知
推荐答案
您应使用异步功能.首先将HTTP请求转换为一个Promise,然后在for循环内异步调用该Promise:
You should use an async function. First convert the HTTP request to a promise, then call that promise asynchronously inside the for loop:
asyncReq (){ return new Promise((resolve, reject) => { this.user.list_upload(JSON.stringify(ins_arr)).subscribe(data=>{ if(data.hasOwnProperty('STATUS')){ if(data.STATUS.toLowerCase()=='success') { this.update(); resolve(); } else if(data.STATUS.toLowerCase() == 'error') { this.user.showToast(data.MESSAGE); reject(); } } },err=>{ this.user.showToast("Error occurred in service file"); reject(err); }); }) } //Async function where loop progresses only after asyncReq completes async asyncForFunction () { for(let i=0; i < final_arr.length; i++){ await this.asyncReq (); } }更多推荐
如何在for循环内等待响应?
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