微信js-sdk，选择图片，上传，下载到本地，php服务端

//前端js代码
<script>  

//客户端6.0.2
wx.config({
    //debug:true,
    appId: "{pigcms:$signPackage.appId}",
    timestamp: {pigcms:$signPackage.timestamp},
    nonceStr: '{pigcms:$signPackage.nonceStr}',
    signature: '{pigcms:$signPackage.signature}',
    url : '{pigcms:$signPackage.url}',
    jsApiList: [
        'checkJsApi',
        'chooseImage',
        'previewImage',
        'uploadImage',
        'downloadImage'
    ]
});
wx.ready(function() {
    // 1 判断当前版本是否支持指定 JS 接口，支持批量判断
    wx.checkJsApi({
        jsApiList: [
            'chooseImage',
            'previewImage',
            'uploadImage',
            'downloadImage',
            'getNetworkType',
            'openLocation',
            'getLocation',
            'downloadVoice'
        ],
        success: function(res) {
            //alert(JSON.stringify(res));
        }
    });
    var images = {
        localId: [],
        serverId: [],
        downloadId: []//可以无视
    };
    var xmlHttpRequest;
    var accessToken=getCookie("accessToken");
    //选择图片
    document.getElementById("selpic").onclick = function() {
        $("#errormsg").append("开始选择图片<br />");
        wx.chooseImage({
            count: 9, // 默认9
            sizeType: ['compressed'], // 可以指定是原图还是压缩图，默认二者都有'original',
            success: function(res) {
                images.localId = res.localIds;// 返回选定照片的本地ID列表，localId可以作为img标签的src属性显示图片
                jQuery(function(){
                    var imglist="";
                    $.each( res.localIds, function(i, n){//这里是显示已选择的图片
                        imglist+='<li ><img src="'+n+'" style="width:95%;height:150px;" /></li>';
                        //$("#errormsg").append("res.localIds:"+n+"<br />");
                    });
                    $("#imageContainer > ul").html(imglist);
                });
            }
        });
    }  

    document.querySelector("#uploadImage").onclick = function () {//绑定onclick事件，如果没有这个按钮，要注释掉代码，不然点击无效
        $("#errormsg").show();
        $("#errormsg").append("<br />开始上传图片");//下文对此div赋值，只为了直观的看到动态效果
        if (images.localId.length == 0) {
            alert('请先选择图片');
            return;
        }
        images.serverId = [];
        var localIds = images.localId;
        uploadimg(localIds);
    }
    var currentproindex=0;
    function getimgtoserver(serverIds){
        //$("#errormsg").append("<br />serverIds length:"+serverIds.length+",");
        var classid=$("#seltype").val();
        var classname=encodeURI($("#seltype option:selected").text());//传汉字需要转一下，php那边再翻转一下就好了
        var serverId=serverIds.pop();//很微妙的方法，每次从数组取一个
        var proname=encodeURI($("#txtname").val());
        var newurl="http://ab.com/i_product.php?action=getwximg&proname="+proname+"&classid="+classid+"&classname="+classname+"&proindex="+currentproindex+"&uname={pigcms:$_SESSION['uname']}&uid={pigcms:$_SESSION['uid']}&token={pigcms:$_SESSION['token']}&wxurl=http://file.api.weixin.qq.com/cgi-bin/media/get&random="+Math.random()+"&accesstoken="+accessToken+"&mediaid="+serverId;//这里拼接地址，给服务器传参，下载图片需要在服务端处理，js请求存在跨域问题，并且，微信里，jq的初始xmlHttpRequest不能用，只能手写了，难道是我不会用jq？
        //$("#errormsg").append("<br />"+newurl);
        //$("#errormsg").append("<br />serverId:"+serverId)
        xmlHttpRequest.open("POST",newurl,true);//防止参数过长，还是用post方法吧
        xmlHttpRequest.onreadystatechange=function(){
            if (xmlHttpRequest.readyState==4){
                if(xmlHttpRequest.status==200){
                    if(serverIds.length>0){
                        currentproindex+=1;
                        getimgtoserver(serverIds);//递归调用，等本次成功，再开始第二个图片的上传操作
                    }
                    else{
                        $("#errormsg").append("<br />上传成功");
                    }
                    //$("#errormsg").append("<br />"+xmlHttpRequest.responseText);
                }
                else{
                    $("#errormsg").append(xmlHttpRequest.status);
                }
            }
            else if(xmlHttpRequest.readyState==1){
                //$("#errormsg").append("<br />初始化成功");
            }
            else if(xmlHttpRequest.readyState==2){
                $("#errormsg").append("<br />正在发送数据");
            }
            else if(xmlHttpRequest.readyState==3){
                $("#errormsg").append("<br />正在等待服务器反馈");
            }
            else{
                $("#errormsg").append("发生错误了。");//+xmlHttpRequest.responseText);
            }
        }
        xmlHttpRequest.send();
    }
function uploadimg(localIds){
    //$("#errormsg").append("<br />localIds length:"+localIds.length);
    var localId = localIds.pop();
    wx.uploadImage({
        localId: localId,
//      isShowProgressTips: 1,
        success: function (res) {
            images.serverId.push(res.serverId);
            //$("#errormsg").append("<br />"+res.serverId+",");
            if(localIds.length > 0){
                uploadimg(localIds);
            }
            else{
                if(window.XMLHttpRequest){
                    xmlHttpRequest=new XMLHttpRequest();
                }else{
                    xmlHttpRequest=new ActiveXObject("MSXML2.XMLHTTP.3.0");//("Microsoft.XMLHTTP");
                }
                $("#errormsg").append("<br />准备处理，请等待...");
                var serverIds=images.serverId;
                getimgtoserver(serverIds);
            }
        },
        fail: function (res) {
            alert("上传失败，请稍候重试");
        }
    });
}  

});
wx.error(function(res) {
    alert(res.errMsg);
});  

//读取cookies
function getCookie(name)
{
    var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)");
    if(arr=document.cookie.match(reg))
        return (arr[2]);
    else
        return null;
}
function initsel(){
    var url="http://abc.com/chat/i_product.php?action=getclothestype&token={pigcms:$_SESSION['token']}";
    //alert(url);
    $.getJSON(url,function(data){
        var str="<option value=''>-请选择-</option>";
        if(data.length>0){
            for(i=0;i<data.length;i++){
                str+="<option value='"+data[i].id+"'>"+data[i].name+"</option>"
            }
        }
        $("#seltype").html(str);
    });
}
$(function(){
    initsel();//初始化下拉菜单
});
</script>  

//php服务端代码
$act = $_GET['action'];
if ($act == 'getwximg') {
    $wxurl=$_GET['wxurl'];
    $access_token=$_GET['accesstoken'];
    $media_id=$_GET['mediaid'];
    $newurl=$wxurl."?access_token=".$access_token."&media_id=".$media_id;//用php去请求获取图片的接口，js直接调用存在跨域问题
    $token=$_GET['token'];
    $uid=$_GET['uid'];
    $uname=$_GET['uname'];
    $proindex=$_GET['proindex'];
    $classid=$_GET['classid'];
    $classname=urldecode($_GET['classname']);//取到的汉字，翻转一下
    $proname=urldecode($_GET['proname']);  

    $fileInfo = downloadWeixinFile($newurl);//通过接口，取结果
    $filename = date("ymdhis",time()).".jpg";//图片名称
    $time = time();
    $newfolder="uploads/".date("y-m-d",$time)."/";//文件夹名称
    saveWeixinFile($newfolder,$filename, $fileInfo["body"]);//把取到的base64代码，保存成图片
    //echo $newurl;
    if($proindex==0){//因为图片是一次性上传的，这里判断一下，第一张作为产品的封面，剩下的作为产品的描述
        $query = "INSERT INTO tp_img(uid,uname,token,createtime,uptatetime,classid,classname,title,pic) VALUE('".$uid."','".$uname."','".$token."','".$time."','".$time."',".$classid.",'".$classname."','".$proname."','http://abc.com/chat/".$newfolder.$filename."')";
        //$query = "INSERT INTO t_ChatMessage(UserCode,Contents,ToUser,IsRead) VALUE('$sendid', '$msg','$toid','0')";
        $result = mysql_query($query) or die("{\"error\":true,\"errorMsg\":\"Error in query: $query. " . mysql_error()."\"}");
    }
    else{
        $query ="select * from tp_img where token='".$token."' order by uptatetime desc limit 1";
        $result = mysql_query($query) or die("{\"error\":true,\"errorMsg\":\"Error in query: $query. " . mysql_error()."\"}");
        $items = array();
        while($row = mysql_fetch_array($result)){
            array_push($items, ($row));
            $query_update="update tp_img set info=CONCAT(info,'','<div style=\"margin-top:3px;\"><img src=\"http://abc.com/chat/".$newfolder.$filename."\" /></div>') where id=$row[id]";//在产品描述的字段上追加内容
            mysql_query($query_update);
        }
    }
    //echo "{\"error\":\""+$rtmsg+"\"}";  

}  

function downloadWeixinFile($url)
{
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_NOBODY, 0);    //只取body头
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    $package = curl_exec($ch);
    $httpinfo = curl_getinfo($ch);
    curl_close($ch);
    $imageAll = array_merge(array('header' => $httpinfo), array('body' => $package));
    return $imageAll;
}  

function saveWeixinFile($newfolder,$filename, $filecontent)
{
    createFolder($newfolder);
    $local_file = fopen($newfolder."/".$filename, 'w');
    if (false !== $local_file){  

        if (false !== fwrite($local_file, $filecontent)) {  

            fclose($local_file);  

        }
    }
}
 function createFolder($path)
 {
  if (!file_exists($path))
  {
   createFolder(dirname($path));
   mkdir($path, 0777);
  }
 }  

//第二种方法

$accessToken = '公众号 AccessToken';
$media_id = 'wx.uploadImage 返回的 serverId';

// 要存在你服务器哪个位置？
$targetName = './tmp/'.date('YmdHis).'.jpg';

$ch = curl_init("http://file.api.weixin.qq.com/cgi-bin/media/get?access_token={$accessToken}&media_id={$serverId}");
$fp = fopen(FCPATH.$targetName, 'wb');
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_exec($ch);
curl_close($ch);
fclose($fp);

//第三种方法
public function doMobileUpload(){
        global $_W,$_GPC;
        load()->classs('weixin.account');
        $accObj= new WeixinAccount();
        $access_token = $accObj->fetch_available_token();

        $media_id = $_GET['media_id'];

        $url = "http://file.api.weixin.qq.com/cgi-bin/media/get?access_token=".$access_token."&media_id=".$media_id;

        $newfolder= ATTACHMENT_ROOT . 'images' . '/hao_time_photos'."/";//文件夹名称
        if (!is_dir($newfolder)) {
             mkdir($newfolder, 0777);
        }
        $picurl = 'images'.'/hao_time_photos'."/".date('YmdHis').rand(1000,9999).'.jpg';
        $targetName = ATTACHMENT_ROOT.$picurl;
        $ch = curl_init($url); // 初始化
        $fp = fopen($targetName, 'wb'); // 打开写入
        curl_setopt($ch, CURLOPT_FILE, $fp); // 设置输出文件的位置，值是一个资源类型
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_exec($ch);
        curl_close($ch);
        fclose($fp);
        echo $picurl;
    }