日期:2014-05-16  浏览次数:20744 次

利用ajax文件上传不成功
做之前不用异步直接测试HTML和PHP都是没问题的(说明下,我的后台用的PHP),但是当我采用AJAX异步上传的时候就出现问题了,本人新手,出于初级学习阶段,希望大家帮我指出下问题。
另外我想向WEB开发方向学习,目前只是熟悉了HTML,css,php(不过库函数没记到几个,基本都是w3c开着写代码),JS刚刚接触,学了一段时间后,我发现自己最基本HTTP协议都没有去看过,请问这样是不是有点本末倒置呢?希望有人能给指出个学习的顺序和重点,感激不尽。
下面上代码
html表单部分(表单具体内容太多,无关紧要,只贴了3个重要部分)
HTML code

<html>
<head>
<title>上传页面</title>
<script type="text/javascript" src="js/upload.js"></script>
</head>
<body>
<form id="uploadform" method="post" ENCTYPE="multipart/form-data">
<input  onclick="show()" type="submit" value="上传" />
</form>
<div style="width:200px;height:80px;background:yellow; float:left" id="uploadshow"></div>
</body>



upload.js(大致就是先请求一张拥有处理表单数据和上传文件的页面,获取处理后的值再请求一张数据库存信息的php页面,那张页面先检测文件是否上传成功,成功就讲数据存入数据库)
JScript code

    function createAjax(){
        var request=false;
        
        //window对象中有XMLHttpRequest存在就是非IE,包括(IE7,IE8)
        if(window.XMLHttpRequest){
            request=new XMLHttpRequest();

            if(request.overrideMimeType){
                request.overrideMimeType("text/xml");
            }
        

        //window对象中有ActiveXObject属性存在就是IE
        }else if(window.ActiveXObject){
            
            var versions=['Microsoft.XMLHTTP', 'MSXML.XMLHTTP', 'Msxml2.XMLHTTP.7.0','Msxml2.XMLHTTP.6.0','Msxml2.XMLHTTP.5.0', 'Msxml2.XMLHTTP.4.0', 'MSXML2.XMLHTTP.3.0', 'MSXML2.XMLHTTP'];

            for(var i=0; i<versions.length; i++){
                    try{
                        request=new ActiveXObject(versions[i]);

                        if(request){
                            return request;
                        }
                    }catch(e){
                        request=false;
                    }
            }
        }
        return request;
    }


var ajax=null;

function show(){
    ajax=createAjax();
    ajax.open("post", "program_upload.php",true);
    ajax.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    ajax.send(document.getElementById("uploadform").submit());
    
    //指定异步处理显示对象
    var obj_uploadshow=document.getElementById("uploadshow");
    
    //回调函数
    ajax.onreadystatechange=function(){
        obj_uploadshow.innerHTML='uploading..';
        if(ajax.readyState==4 && ajax.status==200){
                var file=ajax.responseText;
                eval("var obj="+file);
                var id = obj.id;
                var program_contentadd = obj.program_contentadd;
                var program_date = obj.program_date;
                var program_team = obj.program_team;
                var program_title = obj.program_title;
                var program_author = obj.program_author;
                var program_add = obj.program_add;
                var program_type = obj.program_type;
                
                function upload_sql(){
                    ajax=createAjax();
                    ajax.open("POST", "program_upload_sql.php",true);
                    ajax.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
                    ajax.send('id='+id+'&program_contentadd='+program_contentadd+'&program_date='+program_date+'&program_team='+program_team+'&program_title='+program_title+'&program_author='+program_author+'&program_add='+program_add+'&program_type='+program_type);
                    if(ajax.responseText==null){
                        var continue_send;