jquery +ajax 上传加预览

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script src="/static/jquery-1.12.4.js"></script>




<h3>4.文件上传</h3>

    <input type="file" id="img" />
    <div id="container"></div>
    <a class="btn" onclick="AjaxSubmit6()">上传</a>



<script>
function AjaxSubmit6() {
            //document.getElementById('img')[0]
            var data = new FormData();
            console.log(data)
            data.append('k1','v1');
            data.append('k2','v2');
            data.append('k3',document.getElementById('img').files[0]);
            console.log(data)

            $.ajax({
                url: '/fakeajax',
                type: 'POST',
                data:data,
                success:function (arg) {
                    var ele=document.createElement('img')
                    ele.src='/'+arg.url
                    document.getElementById('container').appendChild(ele)
                },
                 processData: false,  // tell jQuery not to process the data
                 contentType: false  // tell jQuery not to set contentType

            })
        }



</script>

</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .btn{
            display: inline-block;
            padding: 5px 10px;
            background-color: coral;
            color: white;
        }
    </style>
</head>
<body>

    <iframe style="display: none" id="iframe1" name="ifra1"></iframe>
    <form id="fm1" action="/fakeajax" method="POST" enctype="multipart/form-data" target="ifra1">
        <input type="file" name="k3" onchange="uploadFile();" />
    </form>
    <h3>预览</h3>
    <div id="preview">
    </div>
    <script src="/static/jquery-1.12.4.js"></script>
    <script>

        function uploadFile() {
            document.getElementById('iframe1').onload = reloadIframe1;
            document.getElementById('fm1').submit();
        }
        function reloadIframe1() {
            var content = this.contentWindow.document.body.innerHTML;
            var obj = JSON.parse(content);

            var tag = document.createElement('img');
            tag.src = obj.url;
            $('#preview').empty().append(tag);
        }
    </script>
</body>
</html>

iframe+form 上传预览

Java学习内容