ajax.html
    <form action="/ajax_json/" method="POST" target="ifm1">    <!--伪ajax发送,target="ifm1" 使form和iframe建立关系，表单提交通过ifram提交给后台-->
        <iframe id="ifm1" name="ifm1" ></iframe>
        <input type="text" name="username" />
        <input type="text" name="email" />
        <input type="submit" onclick="sumitForm();" value="Form提交"/>
    </form>

    <script type="text/javascript" src="/static/jquery-1.12.4.js"></script>
    <script>

        function getXHR(){       // 兼容函数
            var xhr = null;
            if(XMLHttpRequest){
                xhr = new XMLHttpRequest();
            }else{
                xhr = new ActiveXObject("Microsoft.XMLHTTP");     //创建IE特殊对象
            }
            return xhr;
        }


        function iframeRequest(){             //伪Ajax操作
            var url = $('#url').val();
            $('#ifm').attr('src',url);
        }
    </script>
views.py
def ajax(request):
    return render(request, 'ajax.html')

def ajax_json(request):
    import time
    time.sleep(3)
    print(request.POST)   #打印request.POST内的内容
    ret = {'code': True , 'data': request.POST.get('username')}
    import json
    return HttpResponse(json.dumps(ret))     #向前台发送ret，利用json.dumps()将ret变为字符串