对微信PHPdemo的分析

<?php
/**
* wechat php test
*/


//define your token
define("TOKEN", "weixin");//定义Token的值
$wechatObj = new wechatCallbackapiTest();
$wechatObj->valid();//验证程序,
$wechatObj->responseMsg();//运行程序，一般我们要做的事情，都在函数里实现；
class wechatCallbackapiTest
{
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 = $GLOBALS["HTTP_RAW_POST_DATA"];//通过POST方式获得信息


//extract post data
if (!empty($postStr)){


$postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);
$fromUsername = $postObj->FromUserName;
$toUsername = $postObj->ToUserName;
$keyword = trim($postObj->Content);
$time = time();
$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>"; 
if(!empty( $keyword ))
{
$msgType = "text";
$contentStr = "Welcome to wechat world!";
  $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);//将自己想发送的内容以固定的格式发给用户
  //$textTpl:数据格式，如果想发送图片或其他，文档上都有格式
  //$fromUsername:开发者微信号 ,$toUsername:发送方帐号（一个OpenID） $time:消息创建时间 （整型）
echo $resultStr;
}else{
echo "Input something...";
}


}else {
echo "";
exit;
}
}


private function checkSignature()
{
$signature = $_GET["signature"];
$timestamp = $_GET["timestamp"];
$nonce = $_GET["nonce"]; 


$token = TOKEN;
$tmpArr = array($token, $timestamp, $nonce);
sort($tmpArr);
$tmpStr = implode( $tmpArr );
$tmpStr = sha1( $tmpStr );


if( $tmpStr == $signature ){
return true;
}else{
return false;
}
}
}


?>


注意：第一次验证时，将$wechatObj->responseMsg();注释掉，


当验证成功后，将$wechatObj->valid();注释掉，将wechatObj->responseMsg()加上