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);