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Zhang_derek

7.Ajax

优先级

如果发送的是【普通数据】

  • jQuery
  • XMLHttpRequest
  • iframe

如果发送的是【文件】

  • iframe
  • jQuery(FormData)
  • XMLHttpRequest(FormData)

原生Ajax

 Ajax主要就是使用 【XmlHttpRequest】对象来完成请求的操作,该对象在主流浏览器中均存在(除早起的IE),Ajax首次出现IE5.5中存在(ActiveX控件)

1、XmlHttpRequest对象介绍

XmlHttpRequest对象的主要方法:

a. void open(String method,String url,Boolen async)
   用于创建请求
    
   参数:
       method: 请求方式(字符串类型),如:POST、GET、DELETE...
       url:    要请求的地址(字符串类型)
       async:  是否异步(布尔类型)
 
b. void send(String body)
    用于发送请求
 
    参数:
        body: 要发送的数据(字符串类型)
 
c. void setRequestHeader(String header,String value)
    用于设置请求头
 
    参数:
        header: 请求头的key(字符串类型)
        vlaue:  请求头的value(字符串类型)
 
d. String getAllResponseHeaders()
    获取所有响应头
 
    返回值:
        响应头数据(字符串类型)
 
e. String getResponseHeader(String header)
    获取响应头中指定header的值
 
    参数:
        header: 响应头的key(字符串类型)
 
    返回值:
        响应头中指定的header对应的值
 
f. void abort()
 
    终止请求

主要方法
主要方法
a. Number readyState
   状态值(整数)
 
   详细:
      0-未初始化,尚未调用open()方法;
      1-启动,调用了open()方法,未调用send()方法;
      2-发送,已经调用了send()方法,未接收到响应;
      3-接收,已经接收到部分响应数据;
      4-完成,已经接收到全部响应数据;
 
b. Function onreadystatechange
   当readyState的值改变时自动触发执行其对应的函数(回调函数)
 
c. String responseText
   服务器返回的数据(字符串类型)
 
d. XmlDocument responseXML
   服务器返回的数据(Xml对象)
 
e. Number states
   状态码(整数),如:200、404...
 
f. String statesText
   状态文本(字符串),如:OK、NotFound...

主要属性
主要属性

2.用原生Ajax做个请求

ajax.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <input type="text"/>
    <input type="button" value="Ajax1" onclick="Ajax1();" />
 
    <script>
        function Ajax1(){
            var xhr = new XMLHttpRequest();
            xhr.open('POST', '/ajax_json/',true);
            xhr.onreadystatechange = function(){
                if(xhr.readyState == 4){
                    // 接收完毕
                    var obj = JSON.parse(xhr.responseText);
                    console.log(obj);
                }
            };
            xhr.setRequestHeader('k1','v1');
            // post请求必须加下面这句请求头 不然后台数据拿不到
            xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset-UTF-8');
            xhr.send("name=root;pwd=123");
        }
    </script>
</body>
</html>

views.py

def ajax(request):
    return render(request,'ajax.html')
 
def ajax_json(request):
    print(request.POST)
    ret = {'code':True,'data':None}
    import json
    return HttpResponse(json.dumps(ret))

 3.跨浏览器支持

XmlHttpRequest

  • IE7+, Firefox, Chrome, Opera, etc.

ActiveXObject("Microsoft.XMLHTTP")

  • IE6, IE5
<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>

    <h1>XMLHttpRequest - Ajax请求</h1>
    <input type="button" onclick="XmlGetRequest();" value="Get发送请求" />
    <input type="button" onclick="XmlPostRequest();" value="Post发送请求" />

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

        function GetXHR(){
            var xhr = null;
            if(XMLHttpRequest){
                xhr = new XMLHttpRequest();
            }else{
                xhr = new ActiveXObject("Microsoft.XMLHTTP");
            }
            return xhr;

        }

        function XhrPostRequest(){
            var xhr = GetXHR();
            // 定义回调函数
            xhr.onreadystatechange = function(){
                if(xhr.readyState == 4){
                    // 已经接收到全部响应数据,执行以下操作
                    var data = xhr.responseText;
                    console.log(data);
                }
            };
            // 指定连接方式和地址----文件方式
            xhr.open('POST', "/test/", true);
            // 设置请求头
            xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset-UTF-8');
            // 发送请求
            xhr.send('n1=1;n2=2;');
        }

        function XhrGetRequest(){
            var xhr = GetXHR();
            // 定义回调函数
            xhr.onreadystatechange = function(){
                if(xhr.readyState == 4){
                    // 已经接收到全部响应数据,执行以下操作
                    var data = xhr.responseText;
                    console.log(data);
                }
            };
            // 指定连接方式和地址----文件方式
            xhr.open('get', "/test/", true);
            // 发送请求
            xhr.send();
        }

    </script>

</body>
</html>

伪Ajax

 由于HTML标签的iframe标签具有局部加载内容的特性,所以可以使用其来伪造Ajax请求,进行偷偷的发送请求

 views.py

def ajax(request):
    return render(request,'ajax.html')

def ajax_json(request):
    print(request.POST)
    ret = {'code':True,'data':None}
    import json
    return HttpResponse(json.dumps(ret))

1.Form表单提交到iframe中,页面不刷新

 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <input type="text"/>
    <input type="button" value="Ajax1" onclick="Ajax1();" />
 
    <form action="/ajax_json/" method="POST" target="ifm1"> <!-- target跟iframe进行关联 -->
        <iframe id="ifm1" name="ifm1" ></iframe>
        <input type="text" name="username" />
        <input type="text" name="email" />
        <input type="submit" value="Form提交"/>
    </form>
</body>
</html>

2.Ajax提交到iframe中,页面不刷新

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <input type="text"/>
    <input type="button" value="Ajax1" onclick="Ajax1();" />
 
    <input type='text' id="url" />
    <input type="button" value="发送Iframe请求" onclick="iframeRequest();" />
    <iframe id="ifm" src="http://www.baidu.com"></iframe>
 
    <script src="/static/jquery-1.12.4.js"></script>
    <script>
 
        function iframeRequest(){
            var url = $('#url').val();
            $('#ifm').attr('src',url);
        }
    </script>
</body>
</html>

3.Form表单提交到iframe中,并拿到iframe中的数据

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <input type="text"/>
    <input type="button" value="Ajax1" onclick="Ajax1();" />
 
    <form action="/ajax_json/" method="POST" target="ifm1">
        <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 sumitForm(){
            $('#ifm1').load(function(){
                var text = $('#ifm1').contents().find('body').text();
                var obj = JSON.parse(text);
                console.log(obj)
            })
        }
    </script>
</body>
</html>

文件上传的三种方式

 原生Ajax、Ajax、伪Ajax进行上传文件

 views.py

from django.shortcuts import render,HttpResponse

def upload(request):
    return render(request,'upload.html')

def upload_file(request):
    username = request.POST.get(('username'))
    fafafa = request.FILES.get('fafafa')        #获取文件

    with open(fafafa.name,'wb') as f:
        for item in fafafa.chunks():
            f.write(item)
    print(username,fafafa)
    ret = {'code': True, 'data': request.POST.get('username')}
    import json

    return HttpResponse(json.dumps(ret))

1.原生Ajax(XmlHttpRequest)上传文件+定制好看的上传按钮:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <style>
        .upload{
            display: inline-block;padding: 10px;
            background-color: brown;
            position: absolute;
            top: 0;
            bottom: 0;
            right: 0;
            left: 0;
            z-index: 90;
        }
        .file{
            width: 100px;height: 50px;opacity: 0;
            position: absolute;
            top: 0;
            bottom: 0;
            right: 0;
            left: 0;
            z-index: 100;
        }
    </style>
</head>
<body>
    <div style="position: relative;width: 100px;height: 50px;">
        <input class="file" type="file" id="fafafa" name="afafaf" />
        <a class="upload">上传</a>
    </div>
    <input type="button" value="提交XHR" onclick="xhrSubmit();" />
     
    <script>
        function xhrSubmit(){
            // $('#fafafa')[0]
            var file_obj = document.getElementById('fafafa').files[0];  //获取文件对象
 
            var fd = new FormData();       
            fd.append('username','root');
            fd.append('fafafa',file_obj);
 
            var xhr = new XMLHttpRequest();
            xhr.open('POST', '/upload_file/',true);
            xhr.onreadystatechange = function(){
                if(xhr.readyState == 4){
                    // 接收完毕
                    var obj = JSON.parse(xhr.responseText);
                    console.log(obj);
                }
            };
            xhr.send(fd);
        }
    </script>
</body>
</html>

2.JQuery进行文件的上传:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <style>
        .upload{
            display: inline-block;padding: 10px;
            background-color: brown;
            position: absolute;
            top: 0;
            bottom: 0;
            right: 0;
            left: 0;
            z-index: 90;
        }
        .file{
            width: 100px;height: 50px;opacity: 0;
            position: absolute;
            top: 0;
            bottom: 0;
            right: 0;
            left: 0;
            z-index: 100;
        }
    </style>
</head>
<body>
    <div style="position: relative;width: 100px;height: 50px;">
        <input class="file" type="file" id="fafafa" name="afafaf" />
        <a class="upload">上传</a>
    </div>
{#    <input type="button" value="提交XHR" onclick="xhrSubmit();" />#}
    <input type="button" value="提交jQuery" onclick="jqSubmit();" />
    <div id="preview"></div>
     
    <script src="/static/jquery-1.12.4.js"></script>
    <script>
        function jqSubmit(){
            // $('#fafafa')[0]
            var file_obj = document.getElementById('fafafa').files[0];
 
            var fd = new FormData();
            fd.append('username','root');
            fd.append('fafafa',file_obj);
 
            $.ajax({
                url: '/upload_file/',
                type: 'POST',
                data: fd,
                processData: false,  // tell jQuery not to process the data
                contentType: false,  // tell jQuery not to set contentType
                success:function(arg,a1,a2){
                    console.log(arg);
                    console.log(a1);
                    console.log(a2);
// Object {readyState: 4, responseText: "{"data": "root", "code": true}", status: 200, statusText: "OK"}
                }
            })
        }
    </script>
</body>
</html>

上面两种方式都用到FormData(),但是如果是IE浏览器的话是不支持FormData(),所以就得用到下面这种方式

3.Iframe进行文件的上传:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <form id="form1" action="/upload_file/" method="POST" enctype="multipart/form-data" target="ifm1">
        <iframe id="ifm1" name="ifm1" style="display: none;"></iframe>
        <input type="file" name="fafafa"  />
        <input type="submit" onclick="iframeSubmit();" value="Form提交"/>
    </form>
    <script src="/static/jquery-1.12.4.js"></script>
    <script>
        function iframeSubmit(){
            $('#ifm1').load(function(){
                var text = $('#ifm1').contents().find('body').text();
                var obj = JSON.parse(text);
                console.log(obj)
            })
        }
    </script>
</body>
</html>

上传文件时预览

 1.预览

views.py

def upload(request):
    return render(request,'upload.html')
 
 
def upload_file(request):
    username = request.POST.get(('username'))
    fafafa = request.FILES.get('fafafa')        #获取文件
    import os
    img_path = os.path.join('static/imgs/',fafafa.name)     #static下创建imgs目录
    with open(img_path,'wb') as f:
        for item in fafafa.chunks():
            f.write(item)
    print(username,fafafa)
    ret = {'code': True, 'data': img_path}
    import json
 
    return HttpResponse(json.dumps(ret))

upload.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <form id="form1" action="/upload_file/" method="POST" enctype="multipart/form-data" target="ifm1">
        <iframe id="ifm1" name="ifm1" style="display: none;"></iframe>
        <input type="file" name="fafafa"  />
        <input type="submit" onclick="iframeSubmit();" value="Form提交"/>
    </form>
    <div id="preview"></div>
    <script src="/static/jquery-1.12.4.js"></script>
    <script>
        function iframeSubmit(){
            $('#ifm1').load(function(){
                var text = $('#ifm1').contents().find('body').text();
                var obj = JSON.parse(text);
                console.log(obj)
 
                 $('#preview').empty();
                var imgTag = document.createElement('img');
                imgTag.src = "/" + obj.data;
                $('#preview').append(imgTag);
            })
        }
    </script>
</body>
</html>

2.选择文件后直接上传

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <form id="form1" action="/upload_file/" method="POST" enctype="multipart/form-data" target="ifm1">
        <iframe id="ifm1" name="ifm1" style="display: none;"></iframe>
        <input type="file" name="fafafa" onchange="changeUpalod();" />    //onchange 选中文件时触发
{#        <input type="submit" onclick="iframeSubmit();" value="Form提交"/>#}
    </form>
    <div id="preview"></div>
    <script src="/static/jquery-1.12.4.js"></script>
    <script>
        function changeUpalod(){
            $('#ifm1').load(function(){                //load  绑定load事件,有数据时执行
                var text = $('#ifm1').contents().find('body').text();
                var obj = JSON.parse(text);
 
                $('#preview').empty();
                var imgTag = document.createElement('img');
                imgTag.src = "/" + obj.data;
                $('#preview').append(imgTag);
            });
            $('#form1').submit();
        }
    </script>
</body>
</html>

posted on 2018-02-13 21:12 zhang_derek 阅读(...) 评论(...) 编辑 收藏

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