现在验证是通过了,就差返回给微信那边,我返回echostr还是true 微信那边都说我token验证失败

<?php
namespace app\index\controller;

use think\Request,think\Db;
use think\Cache;
class Autoreply extends RestBase{
    // 获取微信数据
    public function checktoken(){
        $request = Request::instance();
        $get = $request->param();
        $timestamp = $get['timestamp'];//timestamp其实就是一个时间戳  
        $nonce     = $get['nonce'];//nonce是一个随机参数  
        $token     = "";//这个token填写你在微信公众平台上写的那个值  
        $signature = $get['signature'];//这个signature其实就是在微信公众平台已经加密好的字符串  
        $echostr   = $get['echostr'];  
        $array = array();
        $array = array($token,$timestamp,$nonce);
        sort($array);
        $tmpstr = sha1(implode('',$array));  
        if($tmpstr == $signature){
            echo $get['echostr'];
        }else{
            return false;
        }
        
    }
}