微信开发中怎样自动回复？

1.微信开发接入配置所需要的代码如下：

<?php
//define your token
define("TOKEN", "yxy9806");
$wechatObj = new wechatCallbackapiTest();
$wechatObj->run();

class wechatCallbackapiTest
{
	public function run()
    {
		if($this->checkSignature()){//验证请求是否来自服务器
		   die('非法请求');     	
		}

		if(isset($_GET["echostr"])){
		    $echoStr = $_GET["echostr"];
			echo $echoStr;
        	exit;
		}else{
			$this->responseMsg();
		}
        //valid signature , option
        
    }

    public function responseMsg()
    {//自动恢复
		//get post data, May be due to the different environments获取POST数据，可能是由于不同的环境
		$postStr = $GLOBALS["HTTP_RAW_POST_DATA"];//微信向公众号发送的消息 
        file_put_contents('msg.txt', $postStr, FILE_APPEND);//得到消息写入文档
      	//extract post data提取后的数据
		if (!empty($postStr)){
                //simplexml_load_string解析xml字符串，simplexml_load_file解析xml变成节点对象
              	$postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);//获取发送者给谁的内容，时间戳
                $fromUsername = $postObj->FromUserName;
                $toUsername = $postObj->ToUserName;
                $keyword = trim($postObj->Content);//去空格
                $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>";//%s占位符             
				if(!empty( $keyword ))
                {
              		$msgType = "text";
                	$contentStr = "欢迎使用!";
                	$resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);//返回格式化的字符串
                	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);//对数组排序，按键值排序，会破坏原来的键
		$tmpStr = implode( $tmpArr );//数组转换成字符串
		$tmpStr = sha1( $tmpStr );
		
		if( $tmpStr == $signature ){
			return true;
		}else{
			return false;
		}
	}
}

?>

2.关键词回复：写一个关键字的方法在里面判断，代码如下：

 //关键字回复
    public function keyword($k){
        if($k =="放假"){
        	$contentStr = "放假时间2018.04.05";
        }else if($k =="天气"){
        	$contentStr = "今天有小雨";
        }else{
        	$contentStr = "对不起，此关键字无法识别";
        } 
        return $contentStr;
    }
		

方法responseMsg()中需要修改的代码：

if(!empty( $keyword ))
                {
              		$msgType = "text";
                	// $contentStr = "欢迎使用!";
                	$contentStr = $this->keyword($keyword);
                	$resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);//返回格式化的字符串
                	echo $resultStr;
                }else{
                	echo "Input something...";
                }