jquery ajax 上传文件

html:
<!-- /.tab-pane -->
                <div class="tab-pane" id="head_portrait">
                    <!-- The timeline -->
                    <div class="user-block">
                        <div class="col-sm-2">
                            <img class="img-circle img-bordered-sm" src="{% static ""%}{% truncate_url request.user.userprofile.head_portrait %}" alt="user image">
                        </div>
                        <div class="col-sm-6"><form class="form-horizontal ng-pristine ng-valid" role="form" novalidate="" name="form">
                                <div class="avatar-local-wrap">
                                    <p style="margin-bottom: 0">从电脑里挑选一张好图作为头像吧</p>
                                    <div class="clearfix">
                                        <input placeholder="选择一个文件" disabled="disabled" class="form-control" style="width: 176px;display: inline-block">
                                        <div class="btn btn-default">
                                            <span func="select_upload_file">上传</span>
                                            <input name="file00" type="file" class="hide" form-data="formData" id="startUploadBtn" file-reader="" accept=".jpg,.png,.gif">
                                        </div>
                                    </div>
                                    <div func="msg_error1" class="text-danger hide">对不起，格式错误或文件大小超过2M</div>
                                    <p>支持jpg/png/gif格式图片，文件需小于2M</p>
                                </div>
                                <div class="form-group">
                                    <div class="col-sm-offset-0 col-sm-10">
                                        <button type="button" class="btn btn-primary" name="confirm" onclick="UploadFile('#startUploadBtn', 1);">确定</button>
                                        <button type="button" class="btn btn-primary" name="cancel" onclick="UploadFile('#startUploadBtn', 2);">取消</button>
                                    </div>
                                </div>
                            </form>
                        </div>

                    </div>
                </div>
                <!-- /.tab-pane -->

js：
function UploadFile(selector, action){
    //上传文件
    if(action == 1){
         var form_data = new FormData();
        //var name = $('#startUploadBtn').val();
        //form_data.append('file', $('#startUploadBtn')[0].files[0]);
        var name = $(selector).val();
        form_data.append('file', $(selector)[0].files[0]);
        form_data.append('name', name);
        if($(selector)[0].files[0]){
            $.ajax({
                url: '/auth/userprofile/2/',
                type: 'POST',
                data: form_data,
                //告诉jQuery不要去处理发送的数据
                processData : false,
                //告诉jQuery不要去设置Content-Type请求头
                contentType : false,
                //beforeSend: function(){
                //    console.log('正上传中，请稍候');
                //},
                success: function(callback){
                    callback = JSON.parse(callback)['data'];
                    if(callback['status'] == 1){
                        //上传图片成功
                        location.href = window.location.href;
                    }else if(callback['status'] == 2){
                        $('div[func="msg_error1"]').removeClass('hide');
                        $(selector).parent().prev().attr('placeholder', '选择一个文件');
                    }else{
                        //上传图片失败
                        $(selector).parent().prev().attr('placeholder', '选择一个文件');
                    }
                },
                error: function(err){
                    console.log(err);
                }
            });
        }
    }else if(action == 2){
        //取消上传文件
        $('div[func="msg_error1"]').addClass('hide');
        $(selector).val('');
        $(selector).parent().prev().attr('placeholder', '选择一个文件');
    }
}

views.py:
@login_required
def UploadFile(req):
    """
    上传文件
    :param req:
    :return:
    """
    data = {'status':0}
    if req.method == "POST":
        allow_file_type = ['.png', '.jpg', '.gif']
        file_obj = req.FILES.get('file')        # get的key与 jQurey post中的数据key相同，form_data.append('file', $('#startUploadBtn')[0].files[0]);
        # print(file_obj.size, len(file_obj))
        # print(dir(file_obj))
        file_type = re.findall('.\w+$',file_obj.name)[0].lower()
        if file_obj and file_type in allow_file_type and len(file_obj) <= 2097152:       # 判断文件类型为允许的图片类型且文件大小不超过2M，这里的单位是字节，也可以用file_obj.size变量
            file_name = '%s%s%s' %(time.strftime('%Y%m%d%H%M%S',time.localtime(time.time())),random.randrange(10000,99999),file_type)
            db_ImageField_file_name = 'upload/user_image/%s' %(file_name)   # 组合 UserProfile表中head_portrait字段路径，该字段相当于 字符串字段

            # 保存文件，这里边传边写，小于2M的先保存到内存，其他的先保存到系统临时文件，然后再保存到目标文件
            with open('upload/user_image/%s' %(file_name),'wb+')  as fp:
                for chunk in file_obj.chunks():
                    fp.write(chunk)

            user_set = models.UserProfile.objects.filter(user_id=req.user.id)
            user_set.update(head_portrait=db_ImageField_file_name)
            data['status'] = 1
        else:
            data['status'] = 2
    return HttpResponse(json.dumps({'data':data}))