js发送请求

分js、ajax方式发送http请求。

1. js
   在js方法内

   function xxxx() {
       let xhr = new XMLHttpRequest();
       xhr.open("POST", "/admin/qrcode_add");
       xhr.setRequestHeader("Accept", "application/json");
       xhr.setRequestHeader("Content-Type", "application/json");
       xhr.onreadystatechange = function () {
         if (xhr.readyState === 4) {
           console.log(xhr.status);
           console.log(xhr.responseText);
         }};
   
       xhr.send(JSON.stringify(post_params));
   }

2. ajax

   //填写后台给的参数
   var post_params = {"recipient_email": email, "username": username};
   $.ajax({
       type: 'post',
       url: '/send_mail',
       data: JSON.stringify(post_params),
       contentType: 'application/json',
       success: function(res){
           console.log(res);
       }
   });