为什么我echo出来的东西就是一个%s？而不是我赋值的字符串?

完整代码：

IndexAction.class.php

// 本类由系统自动生成，仅供测试用途

class IndexAction extends Action {

public function index(){

$this->responseMsg();

}

public function responseMsg(){

$postStr="

1348831860

1234567890123456

";

$postObj = simplexml_load_string($postStr);

$fromUsername = $postObj->FromUserName;

//echo $fromUsername;

//echo '111';

$toUsername = $postObj->ToUserName;

$time = time();

$msgType = $postObj->MsgType;

$content = $postObj->Content;

if($content=='tel'){

$indexModel=new IndexModel();

$indexModel->responseText($postObj,$content);

}

}

}

IndexModel.class.php

class IndexModel extends Model{

//回复纯文本

public function responseText($postObj,$content) {

$time=time();

$fromUsername = $postObj->FromUserName;

$toUsername = $postObj->ToUserName;

$textTpl = "

%s

";

echo "textTpl is: ".$textTpl;

$resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $content);

// echo $resultStr;

}

}

?>