Question

问题：在Chrome中工作时，脚本不等待同步xhr响应。在FireFox / IE中正常工作。已经使用过onreadyStateHandlers，但是在收到响应之前，仍会执行其他代码。

function callingScript()
{ var a=callServer();
   alert(a);//Here a is showing undefined while executing in chrome. 
            But in FF/IE its waiting for the response and then alerts a with response. 
}

function callServer()
{
 var response;
 var httpRequest = new XMLHttpRequest();
 httpRequest.open("POST","abc",false);
 httpRequest.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
 httpRequest.onreadystatechange = function() 
   {       
        if (httpRequest.readyState != 4)  
           {return; }

        if (httpRequest.status != 200)    
               {response=httpRequest.status;}
        else   {response=httpRequest.responseText;}

   };
 httpRequest.send(data);
 return response;

 }

请分享您的想法!!

Answer 1

函数callServer（）不等待响应请求。使用回调来解决这个问题：

function callingScript()
{ callServer(function(response) {
      alert(response);
  });
}

function callServer(callback)
{
 var response;
 var httpRequest = new XMLHttpRequest();
 httpRequest.open("POST","abc",false);
 httpRequest.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
 httpRequest.onreadystatechange = function() 
   {       
        if (httpRequest.readyState != 4)  
           {return; }

        if (httpRequest.status != 200)    
               {response=httpRequest.status;}
        else   {response=httpRequest.responseText;}

        callback(response);
   };
 httpRequest.send(data);
 return response;

 }

Chrome中的XHR同步调用失败。脚本不等待xhr响应

1 个答案: