php生手求微信PHP的注释

php新手求微信PHP的注释
/**
  * 微信 php 测试
  */

//定义你的token
define("TOKEN", "weixin");
$wechatObj = new wechatCallbackapiTest();
$wechatObj->valid();

class wechatCallbackapiTest
{
public function valid()
    {
$echoStr = $_GET["echostr"];

        //有效签名 , 选项
        if($this->checkSignature()){
         echo $echoStr;
         exit;
        }
    }

    public function responseMsg()
    {
//获取post数据，可能由于环境不同
$postStr = $GLOBALS["HTTP_RAW_POST_DATA "];

       //提取发布数据
if (!empty($postStr)){
                
               $postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_ NOCDATA);
                $fromUsername = $postObj->FromUserName;
                $toUsername = $postObj->ToUserName;
                $keyword = trim($postObj->Content) ;
                $时间 = 时间();
                $textTpl = "


%s

内容>
0
";             
if(!empty( $keyword ))
                {
               $msgType = "text";
                $contentStr = “欢迎来到微信世界！”;
                 $resultStr = sprintf($textTpl , $fromUsername, $toUsername, $time, $msgType, $contentStr);
                 echo $resultStr;
                }else{
                 echo “输入一些内容...”;
                }

        }否则{
         echo "";