application/common/library/wechatWechat.php

<?php
namespace app\common\library\wechat;
use think\Exception;
use think\Db;
/**
 * wechat php test
 */


//define your token
class Wechat
{
    public function valid()
    {
        $echoStr = $_GET["echostr"];

        //valid signature , option
        if($this->checkSignature()){
            echo $echoStr;
            exit;
        }
    }

    public function responseMsg()
    {
        //get post data, May be due to the different environments
        $postStr = file_get_contents("php://input");

        //extract post data
        if (!empty($postStr)){
            /* libxml_disable_entity_loader is to prevent XML eXternal Entity Injection,
             the best way is to check the validity of xml by yourself */
            libxml_disable_entity_loader(true);
            $postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);
            $fromUsername = $postObj->FromUserName; //openid
            $toUsername = $postObj->ToUserName;
            $keyword = trim($postObj->Content);
            $time = time();
            $msgType = $postObj->MsgType;//消息类型
            $event = $postObj->Event;//时间类型，subscribe（订阅）、unsubscribe（取消订阅）
            $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>";

            switch($msgType){
                case "event":
                    if($event=="subscribe"){
                        $contentStr = "Hi,欢迎关注";
                    }
                    break;
                case "text":
                    if(!empty($keyword)){
                        if(preg_match("/^1[34578]\d{9}$/", $keyword)){
                            //这里有无限想象
                            $member =  Db("u_tanfang_member")->where(array('mobile'=>$keyword))->find();
                            if(!empty($member)){
                                Db("u_tanfang_member")->where(array('mobile'=>$keyword))->update(array('wechat_openid'=>$fromUsername));
                            }
                            $member =  Db("u_tanfang_techer")->where(array('mobile'=>$keyword))->find();
                            if(!empty($member)){
                                Db("u_tanfang_techer")->where(array('mobile'=>$keyword))->update(array('wechat_openid'=>$fromUsername));
                            }
                            $contentStr = "Hi,亲已绑定好了,坐等消息回复即可！";
                        }else{
                            echo "";
                            exit;
                        }
                     }
                    break;
            }
            $msgType = "text";
            $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);
            echo $resultStr;
        }else {
            echo "";
            exit;
        }
    }


    private function checkSignature()
    {
        // you must define TOKEN by yourself
        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;
        }
    }
}

?>