笔记：JS异步文件上传

js部分

    function uploadSucc(data){
        alert(data);
    }
    W('#uploadframe').on('load',function(e,uploadSucc){
        e.preventDefault();
        var el = this;
        (function(){
            try{
                var data = el.contentWindow.document.body.getElementsByTagName("TEXTAREA")[0].value;
                data = QW.StringH.evalExp(data);
                console.log(data);
                uploadSucc(data);
            }catch(e){
                setTimeout(arguments.callee,0);
                return;
            }   
        })();
    });

HTML

<form action="<%#site_url#%>setting/upload" enctype="multipart/form-data" method="post" target="uploadframe">
    <input type="file" name="file"/>
    <input type="submit" value="上传"/>
</form>
<iframe id="uploadframe" name="uploadframe"></iframe>