Javascript: 通过图片url获取图片blob对象

function getimage(imageurl){
　　var arr = imageurl.split('/');
 3　　function binaryToArrayBuffer(data) {
   　　var arr = new Uint8Array(data.length);
      for(var i = 0, l = data.length; i < l; i++) {
      　　arr[i] = data.charCodeAt(i);
      }
     return arr.buffer;
  };
                    //获取原始responseTest并转化为arrayBuffer格式
  function getImageArrBuffer(url) {
      var r = new XMLHttpRequest();
      r.open("GET", url, false);
      r.overrideMimeType('text/plain; charset=x-user-defined');
      r.send(null);
      var arrayBuffer = binaryToArrayBuffer(r.responseText);
      arrayBuffer.name = arrayBuffer.fileName = url.substring(url.lastIndexOf('/') + 1);
      arrayBuffer.fileType = "image/jpeg"; //"image/octet-stream";
          return arrayBuffer;
  };
      var response = getImageArrBuffer(imageurl);
         console.log(response);26 }

参考：https://www.cnblogs.com/fengmk2/archive/2011/05/08/2040621.html