使用composer install时报错：
The openssl extension is required for SSL/TLS protection but is not available. If you can not enable the openssl extension, you can disable this error, at y
our own risk, by setting the 'disable-tls' option to true.
Warning: PHP Startup: Unable to load dynamic library 'php_pdo_mysql' (tried: C:\php\ext\php_pdo_mysql (找不到指定的模块。), C:\php\ext\php_php_pdo_mysql.dll (找 不到指定的模块。)) in Unknown on line 0
是扩展问题，然后检查了php.ini中安装了扩展，那就是路径问题，发现缺少了extension_dir属性，添加上路径即正常了。