微信公眾平臺(tái)可以根據(jù)用戶發(fā)送的信息進(jìn)行判斷，然后給出對(duì)應(yīng)的回復(fù)，具有良好的交互性。下文將模擬簡(jiǎn)單的回復(fù)功能，根據(jù)這個(gè)案例，開發(fā)者也可以基本理解微信交互的原理，進(jìn)行更深層次的開發(fā)。

二、思路分析

用戶發(fā)送過來的文本信息，我們可以提取關(guān)鍵字，通過簡(jiǎn)單的 if...elseif...else... 實(shí)現(xiàn)。

關(guān)鍵代碼如下：

if($keyword=="你好"){
　　$contentStr = "hello";
}elseif($keyword=="蘇州"){
　　$contentStr = "上有天堂，下有蘇杭";
}else{
　　$contentStr = "感謝您關(guān)注【卓錦蘇州】 微信號(hào)：zhuojinsz";
}

如果用戶發(fā)送"你好"，則回復(fù)"hello"，如果用戶發(fā)送"蘇州"，則回復(fù)"上有天堂，下有蘇杭"，其他信息，則回復(fù)你的歡迎詞。

三、完整代碼

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

//define your token
define("TOKEN", "zhuojin");
$wechatObj = new wechatCallbackapiTest();
$wechatObj->responseMsg();
//$wechatObj->valid();

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"];

     //extract post data
    if (!empty($postStr)){
        
         $postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);
        $RX_TYPE = trim($postObj->MsgType);

        switch($RX_TYPE)
        {
          case "text":
            $resultStr = $this->handleText($postObj);
            break;
          case "event":
            $resultStr = $this->handleEvent($postObj);
            break;
          default:
            $resultStr = "Unknow msg type: ".$RX_TYPE;
            break;
        }
        echo $resultStr;
    }else {
      echo "";
      exit;
    }
  }

  public function handleText($postObj)
  {
    $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";

      if($keyword=="你好"){
        $contentStr = "hello";
      }elseif($keyword=="蘇州"){
        $contentStr = "上有天堂，下有蘇杭";
      }else{
        $contentStr = "感謝您關(guān)注【卓錦蘇州】 微信號(hào)：zhuojinsz";
      }
      $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);
      echo $resultStr;
    }else{
      echo "Input something...";
    }
  }

  public function handleEvent($object)
  {
    $contentStr = "";
    switch ($object->Event)
    {
      case "subscribe":
        $contentStr = "感謝您關(guān)注【卓錦蘇州】"."\n"."微信號(hào)：zhuojinsz"."\n"."卓越錦繡，名城蘇州，我們?yōu)槟峁┨K州本地生活指南，蘇州相關(guān)信息查詢，做最好的蘇州微信平臺(tái)。"."\n"."目前平臺(tái)功能如下："."\n"."【1】 查天氣，如輸入：蘇州天氣"."\n"."【2】 查公交，如輸入：蘇州公交178"."\n"."【3】 翻譯，如輸入：翻譯I love you"."\n"."【4】 蘇州信息查詢，如輸入：蘇州觀前街"."\n"."更多內(nèi)容，敬請(qǐng)期待...";
        break;
      default :
        $contentStr = "Unknow Event: ".$object->Event;
        break;
    }
    $resultStr = $this->responseText($object, $contentStr);
    return $resultStr;
  }
  
  public function responseText($object, $content, $flag=0)
  {
    $textTpl = "<xml>
          <ToUserName><![CDATA[%s]]></ToUserName>
          <FromUserName><![CDATA[%s]]></FromUserName>
          <CreateTime>%s</CreateTime>
          <MsgType><![CDATA[text]]></MsgType>
          <Content><![CDATA[%s]]></Content>
          <FuncFlag>%d</FuncFlag>
          </xml>";
    $resultStr = sprintf($textTpl, $object->FromUserName, $object->ToUserName, time(), $content, $flag);
    return $resultStr;
  }


  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;
    }
  }
}

?>

四、測(cè)試