Problems related to smarty loading

An error occurred while loading smarty init. inc. phpPHPcodedefine (, str_replace (\, dirname (_ FILE _); includeExtSmarty. class. php; classTplextendsSmarty {function smarty loading
Init. inc. php

PHP code

  define ( '', str_replace ( '\\', '/', dirname ( __FILE__ ) ) );include 'Ext/Smarty.class.php';class Tpl extends Smarty {    function __construct() {        $this->setTemplateDir ( ."/View" );        $this->setCompileDir (."./comp_c" );        $this->left_delimiter = "<{";        $this->right_delimiter = "}>";        parent::__construct();    }}

Index. php

PHP code

  include 'init.inc.php';class Index extends Tpl {    function index(){        $this->assign('m','asdfasdfasdf');                $this->display('index.html');    }}$tpl = new Index();$tpl->index();

The error message for the Smarty-3.1.11 version is:

PHP code

  Fatal error: Call to a member function createTemplate() on a non-object in D:\AppServ\www\smarty\Ext\sysplugins\smarty_internal_templatebase.php on line 47

It's just that I use a common method to avoid problems, such:

PHP code

  $smarty = new Smarty();$smarty->setTemplateDir (  . "/View" );$smarty->setCompileDir (  . "/comp_c" );$smarty -> left_delimiter="<{";$smarty -> right_delimiter="}>";include "init.inc.php";$smarty->display("demo.tpl");

I have not solved the problem for a day. I don't know where the problem occurs. please help me...

------ Solution --------------------
Look at your print_r ($ this-> Smarty );
It should not be instantiated successfully, that is, $ this-> Smarty is not a Smarty object