Laravel 安装时Require(D:\myphp_www\PHPTutorial\WWW\blog/vendor/autoload.php): failed to open stream: N

最近在学习Laravel 框架在运行 php artisan serve后出现

PHP Warning:  require(D:\myphp_www\PHPTutorial\WWW\blog/vendor/autoload.php): failed to open stream: No such file or directory 

的报错，运行

composer dump-autoload

清空编译文件之后恢复正常。