PDO连接mysql8.0报PDO::__construct(): Server sent charset (255) unknown to the client. Please, report to the developers错误

安装mysql8.0之后，尝试使用php连接mysql，总是报PDO::__construct(): Server sent charset (255) unknown to the client. Please, report to the developers错误，网上找了很多资料，然而都没有多大用处。

查找了mysql官方说明文档才知道原来M8.0已经已经把默认字符集升级成ut8mb4了，于是找到my.cnf文件，修改如下：

 1 [client]
  2 port = 3306
  3 socket = /tmp/mysql.sock
  4 default-character-set = utf8
  5
  6 [mysql]
  7 prompt="MySQL [\d]> "
  8 no-auto-rehash
  9 default-character-set = utf8
 10
 11 [mysqld]
 12 port = 3306
 13 socket = /tmp/mysql.sock
 14 default_authentication_plugin = mysql_native_password
 15 collation-server = utf8_unicode_ci
 16
 17 basedir = /usr/local/mysql
 18 datadir = /data/mysql
 19 pid-file = /data/mysql/mysql.pid
 20 user = mysql
 2 bind-address = 0.0.0.0
 22 server-id = 1
 23
 24 init-connect = 'SET NAMES utf8'
 25 character-set-server = utf8

然后使用PDO连接mysql

$db = array(
    'host' => 'your host',         //设置服务器地址
    'port' => '3306',              //设端口
    'dbname' => 'your db name',    //设置数据库名
    'username' => 'your name',     //设置账号
    'password' => 'your pwd',      //设置密码
    'charset' => 'utf8',           //设置编码格式
    'dsn' => 'mysql:host=your host;dbname=your db name;port=3306;charset=utf8',
);  

//连接
$options = array(
    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION, 　　　　//默认是PDO::ERRMODE_SILENT, 0, (忽略错误模式)
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,   // 默认是PDO::FETCH_BOTH, 4
);  

try{
    $pdo = new PDO($db['dsn'], $db['username'], $db['password'], $options);
    var_dump($pdo);
}catch(PDOException $e){
    die('数据库连接失败:' . $e->getMessage());
}

结果如下：

object(PDO)#1 (0) { }