<?php
//写你自己的token
define("TOKEN", "weixin");
$wechatObj = new wechatCallbackapiTest();
//接口验证
/*$wechatObj->valid();*/

//调用回复消息方法
$wechatObj->responseMsg();
class wechatCallbackapiTest{
    //验证方法
    public function valid(){
        $echoStr = $_GET["echostr"];
        if($this->checkSignature()){
            echo $echoStr;
            exit;
        }
    }

    //消息回复
    public function responseMsg(){
        $postStr = $GLOBALS["HTTP_RAW_POST_DATA"];
        //如果用户有请求
        if (!empty($postStr)){
            libxml_disable_entity_loader(true);
            //用户请求的对象
            $postObj = simplexml_load_string($postStr, \'SimpleXMLElement\', LIBXML_NOCDATA);
            $fromUsername = $postObj->FromUserName;
            $toUsername = $postObj->ToUserName;
            //用户输入的文字
            $keyword = trim($postObj->Content);
            $time = time();
            //消息类型
            $msgType = $postObj->MsgType;
            //事件类型
            $event = $postObj->Event;
            //xml模板
            $textTpl = "<xml>
              <ToUserName><![CDATA[%s]]></ToUserName>
              <FromUserName><![CDATA[%s]]></FromUserName>
              <CreateTime>%s</CreateTime>
              <MsgType><![CDATA[%s]]></MsgType>
              <Content><![CDATA[%s]]></Content>
              <FuncFlag>0</FuncFlag>
              </xml>";

            //如果用户的请求类型是事件
            if($msgType=="event"){
                if($event=="subscribe"){
                    $contentStr = "欢迎词";
                }

            }

            //用户的请求类型是文本
            if($msgType=="text"){
                $contentStr =$keyword;
                $msgType = "text";                                    
            }

            //自动填充xml
            $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);
            //回复
            echo $resultStr;
        }
        //用户没有请求
        else{
            echo "";
            exit;
        }
    }

    //验证
    private function checkSignature(){
        if (!defined("TOKEN")) {
            throw new Exception(\'TOKEN is not defined!\');
        }
        $signature = $_GET["signature"];
        $timestamp = $_GET["timestamp"];
        $nonce = $_GET["nonce"];
  
        $token = TOKEN;
        $tmpArr = array($token, $timestamp, $nonce);
        // use SORT_STRING rule
        sort($tmpArr, SORT_STRING);
        $tmpStr = implode( $tmpArr );
        $tmpStr = sha1( $tmpStr );
        if( $tmpStr == $signature ){
            return true;
        }else{
            return false;
        }
    }

}