PHP微信开发之微信消息自动回复下所遇到的坑

<span style="font-family:Courier New;font-size:14px;"><?php 
define("TOKEN","weixin"); 
$weixinObj = new Wechat(); 
$weixinObj->valid(); 
class Wechat{ 
public function valid(){ 
$echoStr = $_GET['echostr']; 
//如果是第一次接入 
if($this->checkSignature() && $echoStr ){ 
echo $echoStr; 
exit; 
}else{ 
$this->responseMsg(); 
} 
} 
//校验方法 
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; 
} 
} 
/* 普通文本消息 
<xml> 
<ToUserName><![CDATA[toUser]]></ToUserName> 
<FromUserName><![CDATA[fromUser]]></FromUserName> 
<CreateTime>1348831860</CreateTime> 
<MsgType><![CDATA[text]]></MsgType> 
<Content><![CDATA[this is a test]]></Content> 
</xml> 
*/ 
public function responseMsg(){ 
//获取微信服务器POST请求中的数据 
$postStr = $GLOBALS["HTTP_RAW_POST_DATA"]; 
if( !empty($postStr) ){ 
$postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA); 
$fromUser = $postObj->FromUserName; 
$toUser = $postObj->ToUserName; 
$keyword = trim($postObj->Content); 
$time = time(); 
$template = "<xml> 
<ToUserName><![CDATA[%s]]></ToUserName> 
<FromUserName><![CDATA[%s]]></FromUserName> 
<CreateTime>%s</CreateTime> 
<MsgType><![CDATA[%s]]></MsgType> 
<Content><![CDATA[%s]]></Content> 
</xml>"; 
if( strtolower($postObj->MsgType)!='text' ){ 
$msgType = "text"; 
$content = "我只接受文本消息"; 
}else{ 
$msgType = "text"; 
if( !empty($keyword) ){ 
$content = "您发送的消息是：".$postObj->Content; 
}else{ 
$content = "请输入关键字";//消息为空 
} 
} 
$info = sprintf($template, $fromUser, $toUser, $time, $msgType, $content); 
echo $info; 
}else{ 
echo ""; 
exit; 
} 
} 
}</span> 

<span style="font-family:Courier New;font-size:14px;"><?php 
define("TOKEN","weixin"); 
$weixinObj = new Wechat(); 
$weixinObj->valid(); 
class Wechat{ 
public function valid(){ 
$echoStr = $_GET['echostr']; 
//如果是第一次接入 
if($this->checkSignature() && $echoStr ){ 
echo $echoStr; 
exit; 
}else{ 
$this->responseMsg(); 
} 
} 
//校验方法 
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; 
} 
} 
/* 接收图片消息格式 
<xml> 
<ToUserName><![CDATA[toUser]]></ToUserName> 
<FromUserName><![CDATA[fromUser]]></FromUserName> 
<CreateTime>1348831860</CreateTime> 
<MsgType><![CDATA[image]]></MsgType> 
<PicUrl><![CDATA[this is a url]]></PicUrl> 
<MediaId><![CDATA[media_id]]></MediaId> 
<MsgId>1234567890123456</MsgId> 
</xml> 
*/ 
public function responseMsg(){ 
//获取微信服务器POST请求中的数据 
$postStr = $GLOBALS["HTTP_RAW_POST_DATA"]; 
if( !empty($postStr) ){ 
$postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA); 
$fromUser = $postObj->FromUserName; 
$toUser = $postObj->ToUserName; 
$time = time(); 
$msgType= $postObj->MsgType; 
$picUrl = $postObj->PicUrl; 
$mediaId = $postObj->MediaId; 
$template = "<xml> 
<ToUserName><![CDATA[%s]]></ToUserName> 
<FromUserName><![CDATA[%s]]></FromUserName> 
<CreateTime>%s</CreateTime> 
<MsgType><![CDATA[%s]]></MsgType> 
<Content><![CDATA[%s]]></Content> 
</xml>"; 
if( strtolower($msgType)!='image' ){ 
$msgType = "text"; 
$content = "我只接受图片消息"; 
}else{ 
$msgType = "text"; 
if( !empty( $picUrl ) ){ 
$content = "图片链接为:".$picUrl."\n"; 
$content .= "媒体id:".$mediaId; 
}else{ 
$content = "请发送图片";//消息为空 
} 
} 
$info = sprintf($template, $fromUser, $toUser, $time, $msgType, $content); 
echo $info; 
}else{ 
echo ""; 
exit; 
} 
} 
}</span>