报错信息：
phpMyAdmin tried to connect to the MySQL server, and the server rejected the connection. You should check the host, username and password in your configuration and make sure that they correspond to the information given by the administrator of the MySQL server.
这个是由于修改了mysql密码导致的。
解决办法：
修改config.inc.php配置文件
/* Authentication type and info */
$cfg['Servers'][$i]['auth_type'] = 'config';
$cfg['Servers'][$i]['user'] = 'root';
$cfg['Servers'][$i]['password'] = ''; // 填上你的密码。
$cfg['Servers'][$i]['extension'] = 'mysql';
$cfg['Servers'][$i]['AllowNoPassword'] = true;
$cfg['Lang'] = '';
完了可能要重启xampp服务，如果还是不行，尝试清空你的浏览器的缓存。
