ajax上传文件的三种方法

第一种xhr提交

        function xhrSubmit(){
            // $(\'#fafafa\')[0]
            var file_obj = document.getElementById(\'fafafa\').files[0];

            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);
        }

第二种jQuery的ajax提交

        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);
                }
            })
        }

jQuery的ajax默认会做字符拼接,为了能够让文件正常上传定义如下:
processData: false, // tell jQuery not to process the data
contentType: false, // tell jQuery not to set contentType

第三种就是利用ifram来进行上传文件

HTML文件

   <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();" />
{#        <input type="submit" onclick="iframeSubmit();" value="Form提交"/>#}
    </form>

在function只需要写这些就行
function iframeSubmit(){
            $(\'#ifm1\').load(function(){
                var text = $(\'#ifm1\').contents().find(\'body\').text();
                var obj = JSON.parse(text);
            })
        }

views.py

def upload_file(request):
    username = request.POST.get(\'username\')
    fafafa = request.FILES.get(\'fafafa\')
    import os
    img_path = os.path.join(\'static/imgs/\',fafafa.name)
    with open(img_path,\'wb\') as f:
        for item in fafafa.chunks():
            f.write(item)

    ret = {\'code\': True , \'data\': img_path}
    import json
    return HttpResponse(json.dumps(ret))

文件上传预览

        function changeUpalod(){
            $(\'#ifm1\').load(function(){
                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();
        }