原创ajax文件无刷新上传

function submitFun() {
            var files = [document.getElementById('sc')];
            ajaxUploadFile({url:'Index.aspx','files':files,success:function(){alert('success');}});

        }


        //{url, files, data,success,error}
        function ajaxUploadFile(ajaxOptions) {
            var iframeName = 'tmp_iframe';
            var newform, iframe;
            var body = document.body;
            //服务器的返回值
            var xml = {};
            var url = ajaxOptions.url;
            var files = ajaxOptions.files;
            var data = ajaxOptions.data;
            var success = ajaxOptions.success;
            var error = ajaxOptions.error;

            //一个对象数组，对象有两个属性，一个表示临时input文件上传框，一个表示原始文件上传框
            var fileArr = [];

            //提交完成或者超时后的回调函数
            var uploadedCallback = function(timeout) {
                try {
                    //如果不是因为超时才调用此回调函数
                    if ('timeout' != timeout) {
                        if (iframe.contentWindow) {
                            xml.responseText = iframe.contentWindow.document.body ? iframe.contentWindow.document.body.innerHTML : null;
                            xml.responseXML = iframe.contentWindow.document.XMLDocument ? iframe.contentWindow.document.XMLDocument : io.contentWindow.document;

                        } else if (iframe.contentDocument) {
                            xml.responseText = io.contentDocument.document.body ? iframe.contentDocument.document.body.innerHTML : null;
                            xml.responseXML = io.contentDocument.document.XMLDocument ? iframe.contentDocument.document.XMLDocument : io.contentDocument.document;
                        }
                        success(xml.responseText, xml.responseXML);
                    } else {

                    }
                } catch (e) {
                    if(error)
                    {
                         error(e);
                    }
                }
                div.parentNode.removeChild(div);
                //newform.parentNode.removeChild(newform);
                //iframe.parentNode.removeChild(iframe);
            }

            /*
            //创建一个新的form，用于暂时保存上传文件框，hidden控件等
            var newform = document.createElement('form');
            newform.action = url;
            newform.enctype = 'multipart/form-data';
            newform.method = 'post';
            newform.target = iframeName;
            newform.style.display = 'none';
            newform.id = "newform";
            newform.name = 'newfrom';
            
            
            //创建一个IFrame，用于做新的form的提交后显示服务器返回内容的窗口
            var iframe = document.createElement('iframe');
            iframe.name = iframeName;
            //将newform和iframe添加到body
            body.appendChild(iframe);
            body.appendChild(newform);
            */
            var str = '<form action="' + url + '" enctype="multipart/form-data" method="post" target="' + iframeName + '"></form><iframe name="' + iframeName + '"></iframe>';
            var div = document.createElement('div');
            div.innerHTML = str;
            div.style.display = "none";
            newform = div.getElementsByTagName('form')[0];
            iframe = div.getElementsByTagName('iframe')[0];
            body.appendChild(div);
            iframe.onload = uploadedCallback;
            if (iframe.attachEvent) {
                iframe.attachEvent('onload', uploadedCallback);
            }

            for (var i = 0; i < files.length; i++) {
                var newfile = files[i].cloneNode(true);
                fileArr.push({ tmpfile: newfile, orifile: files[i] });
                files[i].parentNode.insertBefore(newfile, files[i]);
                newform.appendChild(files[i]);
            }
            //根据一些自定义的数据，创建input[type=file]，添加到新的form
            if (data) {
                for (var attr in data) {
                    var hidden = document.createElement('input');
                    hidden.type = 'hidden';
                    hidden.name = attr;
                    hidden.value = data[attr];
                    newform.appendChild(hidden);
                }
            }
            if (ajaxOptions.timeout) {
                setTimeout(function() { uploadedCallback('timeout'); }, ajaxOptions.timeout);
            }
            //提交form
            newform.submit();
            //恢复原始文件上传框
            for (i = 0; i < fileArr.length; i++) {
                fileArr[i].tmpfile.parentNode.insertBefore(fileArr[i].orifile, fileArr[i].tmpfile);
                fileArr[i].tmpfile.parentNode.removeChild(fileArr[i].tmpfile, true);
            }
            //newform.parentNode.removeChild(newform);
            //iframe.parentNode.removeChild(iframe);
        }