angularjs – 使用$http访问原始XHR对象

uploadFile(file,progressHandler) {
  var xhr = new XMLHttpRequest(),deferred = $q.defer();

  xhr.open("POST","your/path",true); // method,url,async
  xhr.setRequestHeader("Content-Type",file.type || "application/octet-stream");
  xhr.onreadystatechange = function (e) {
    if (xhr.readyState == 4) {
      $rootScope.$apply(function () {
        // Construct a response object similar to a regular $http call
        //
        // data – {string|Object} – The response body transformed with the transform functions.
        // status – {number} – HTTP status code of the response.
        // headers – {function([headerName])} – Header getter function.
        // config – {Object} – The configuration object that was used to generate the request.
        var r = {
          data: xhr.response,status: xhr.status,headers: xhr.getResponseHeader,config: {}
        };
        if (r.status == 200) {
          deferred.resolve(r);
        } else {
          deferred.reject(r);
        }
      });
    }
  };
  if (progressHandler && xhr.upload) {
    xhr.upload.addEventListener('progress',function(e) {
      progressHandler((e.loaded / e.total),e);
    },false);
  }
  // This is only available in XHR2,provide multipart fallback
  // if necessary
  xhr.send(file);

  return deferred.promise;
}