代码如下：
运行之后test.txt没有被创建，是什么原因呢？
我的php版本7.1.4
apache 2.4.25 (Win32)

<?php

class CTestApp {
    
    public function __construct()
    {
        echo 'CTestApp:';
    }
    
    public function __destruct()
    {
        echo ':the end';

        //failed
        $fp = fopen('test.txt', 'a');
        fwrite($fp, "end of CApplication\r\n");
        fclose($fp);
    }

    public function Ontest()
    {
        echo 'test';
        //exit();
    }
}

$obj = new CTestApp;
$obj->Ontest();