已配置django-cors-headers，Django跨域访问json还是不成功

报错信息：

Setting.py配置和Html调用代码：

ALLOWED_HOSTS = ['*']

# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'corsheaders',
    'visualization',
    'management'
]


MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'corsheaders.middleware.CorsMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

CORS_ALLOW_CREDENTIALS = True
CORS_ORIGIN_ALLOW_ALL = True
CORS_ORIGIN_WHITELIST = (
    '*'
)

$.ajax({
        url:'http://api.k780.com/?app=weather.pm25&weaid=1&appkey=10003&sign=b59bc3ef6191eb9f747dd4e83c99f2a4&format=json',
        type:'GET',
        success:function(data){
            console.log(data);
        }
    });