c# - :'Unable to connect to any of the specified MySQL hosts.' 错误

Question

我想使用连接字符串连接到 MySQl 数据库，但无法连接我正在使用 UWP 并将秋季创建者版本用于目标版本和最小版本

我已经为 Mysql 连接器安装了 Nuget 包我试过更改带和不带端口等的字符串。

public string GetMatchCode()
{        
        string connectString = "Server=###.###.###.###;Database=Db;Uid=root;Pwd=123;sslmode=none;port=3306";
        string sql = "SELECT * FROM `customer`";
        using (var connect = new MySqlConnection(connectString))
        using (var command = new MySqlCommand(sql, connect))
        {             
            connect.Open();
            return command.ExecuteScalar().ToString();
        }
}

MySql.Data.MySqlClient.MySqlException: 'Unable to connect to any of the specified MySQL hosts.' MySqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. The error starts at connect.Open();

我已经测试了与 Workbench 的连接以确保其正常工作。我浏览了大多数类似的帖子，但没有一个对我有用。

Answer 1

连接失败的情况有很多种。请参阅以下几点来解决您的错误。

1. Check your Windows Firewall to ensure that server has an access to Port's associated with your MySql.
2. Disconnect and re-connect your VPN client.
3. Follow standard Spacing and Order of parameters in connection string. Follow below format to build/form connection string. Server=ServerAddress; Port=4563; Database=DataBaseName; Uid=UserName;
Pwd=Password;
4. Consider using Connection Pulling, So existing connection will be reused.