$http({
　　method: ‘POST‘,
　　url: ‘/wechatapp/User/setAvatar‘,
  data: data,
  headers: {
    ‘Content-Type‘: undefined
  },
  transformRequest: function(data) {
    var formData = new FormData();
    formData.append(‘avatar_data‘, data.adata);
    formData.append(‘avatar_file‘, data.file);
    return formData;
  },
  data: {
    adata: scope.avatar_data,
    file: scope.avatar_file
  }
  }).success(function(d) {
    //请求成功
    cb(d);
  }).error(function(err, status) {
    console.log(err);
    cb(err);
  });