1

SigWebRefresh我有这行代码以指定的时间间隔（50毫秒）调用该函数。

tmr = setInterval(SigWebRefresh, 50);

SigWebRefresh执行XMLHTTPRequest：

function SigWebRefresh(){   
    xhr2 = new XMLHttpRequest();    
    xhr2.open("GET", baseUri + "SigImage/0", true );
    xhr2.responseType = "blob"; 
    xhr2.onload = function (){
        var img = new Image();      
        img.src = getBlobURL(xhr2.response);        
        img.onload = function (){           
           Ctx.drawImage(img, 0, 0);
           revokeBlobURL( img.src );
           img = null;
        }
    }   
    xhr2.send(null);
}

我曾经使用clearInterval它清除使用 setInterval() 方法设置的计时器。

 clearInterval(tmr);

我想中止所有 XMLHttpRequest 但xhr2.abort();只中止请求的一个实例。如何中止所有未完成的XmlHttpRequest？

4

3 回答 3

3

尝试将每个xhr2变量推入一个数组，利用Array.prototype.forEach中止xhr2存储的每个变量

var requests = [];

function SigWebRefresh(){   
    xhr2 = new XMLHttpRequest();
    requests.push(xhr2);    
    xhr2.open("GET", baseUri + "SigImage/0", true );
    xhr2.responseType = "blob"; 
    xhr2.onload = function (){
        var img = new Image();      
        img.src = getBlobURL(xhr2.response);        
        img.onload = function (){           
           Ctx.drawImage(img, 0, 0);
           revokeBlobURL( img.src );
           img = null;
        }
    }   
    xhr2.send(null);
}

// abort all requests
requests.forEach(function(request) {
  request.abort()
})
于 2015-10-02T03:31:38.467 回答
0

您可以实现所有处理请求的列表：

function remove(array, element){
    var index = array.indexOf(element);
    if (index > -1) {
        array.splice(index, 1);
    }
}

var all_requests = [] // The list of requests that are processing
function SigWebRefresh(){   
    var xhr2 = new XMLHttpRequest();    
    xhr2.open("GET", baseUri + "SigImage/0", true );
    xhr2.responseType = "blob"; 
    xhr2.onload = function (){
        var img = new Image();      
        img.src = getBlobURL(xhr2.response);        
        img.onload = function (){           
           Ctx.drawImage(img, 0, 0);
           revokeBlobURL( img.src );
           img = null;
           remove(all_requests, xhr2); // Make sure to remove already finished requests from your list
        }
    }   
    xhr2.send(null);
    all_requests.push(xhr2); // Add processing request to the list
}

然后清除：

for(var i in all_requests)
    all_requests[i].abort();
all_requests = [] // Clear the list of requests
于 2015-10-02T03:31:47.473 回答
0 
 var xhr2 = null;

 function SigWebRefresh(){  
      if( xhr2 != null ) {
            xhr2.abort();
            xhr2 = null;
      }
      xhr2 = new XMLHttpRequest();    
      xhr2.open("GET", baseUri + "SigImage/0", true );
      xhr2.responseType = "blob"; 
      xhr2.onload = function (){
        var img = new Image();      
        img.src = getBlobURL(xhr2.response);        
        img.onload = function (){           
           Ctx.drawImage(img, 0, 0);
           revokeBlobURL( img.src );
           img = null;
        }
     }   
     xhr2.send(null);
 }
于 2015-10-02T03:32:59.377 回答