PHP微信公众号开发入门

<?php
include_once "WXBizMsgCrypt.php";
$encodingAesKey = "在公众号设置中指定";
$token = "在公众号设置中指定";
define('TOKEN', $token);
$AppId="在公众号设置中指定";

header("Content-Type:text/html; charset=utf-8");

if(is_array($_GET)&&count($_GET)>0){
    $signature = $_GET["signature"];
    $timestamp = $_GET["timestamp"];
    $nonce = $_GET["nonce"];
	if ($_GET['echostr']){
	    $token = TOKEN;
        $tmpArr = array($token, $timestamp, $nonce);
        sort($tmpArr, SORT_STRING);
        $tmpStr = implode( $tmpArr );
        $tmpStr = sha1( $tmpStr );
        if( $tmpStr == $signature ){
            echo($_GET['echostr']);
        }else{
            print("ERR: " . $errCode . "\n\n");
        }
    	exit;
	}
    $sReqMsgSig = $sVerifyMsgSig = $_GET['msg_signature'];  
	$sReqTimeStamp = $sVerifyTimeStamp = $_GET['timestamp'];  
	$sReqNonce = $sVerifyNonce = $_GET['nonce'];  
    $sMsg = ""; 
	$wxcpt = new WXBizMsgCrypt($token, $encodingAesKey, $AppId);
	$errCode = $wxcpt->DecryptMsg($sReqMsgSig, $sReqTimeStamp, $sReqNonce, $sReqData, $sMsg);  
    if ($errCode == 0) {
		$xml = new DOMDocument();  
		$xml->loadXML($sMsg);   
		$reqToUserName = $xml->getElementsByTagName('ToUserName')->item(0)->nodeValue;  
		$reqFromUserName = $xml->getElementsByTagName('FromUserName')->item(0)->nodeValue;  
		$reqCreateTime = $xml->getElementsByTagName('CreateTime')->item(0)->nodeValue;  
		$reqMsgType = $xml->getElementsByTagName('MsgType')->item(0)->nodeValue;  
		$reqContent = $xml->getElementsByTagName('Content')->item(0)->nodeValue;  
		$reqMsgId = $xml->getElementsByTagName('MsgId')->item(0)->nodeValue;  
		$reqAgentID = $xml->getElementsByTagName('AgentID')->item(0)->nodeValue;
		if ($reqMsgType!="text"){
			exit;
		}
        
        $mycontent=$reqContent;
        $timestamp = $_GET['timestamp'];
        $nonce = $_GET['nonce'];
        $toUser   = $reqFromUserName;
        $fromUser = $reqToUserName;
        $respondMsg =  '<xml><ToUserName><![CDATA['.$toUser.']]></ToUserName><FromUserName><![CDATA['.$fromUser.']]></FromUserName><CreateTime>'.time().'</CreateTime><MsgType><![CDATA[text]]></MsgType><Content><![CDATA['.$mycontent.']]></Content></xml>';
            //输出未加密消息
            // echo $respondMsg;
            // exit();
        //输出未加密消息
        $pc = new WXBizMsgCrypt($token, $encodingAesKey, $AppId);
        $encryptMsg = '';
        $errCode = $pc->encryptMsg($respondMsg, $timestamp, $nonce, $encryptMsg);
        echo $encryptMsg;
        exit;
}