无法将C＃程序与MySQL数据库连接

Question

我在连接mysql和C＃程序时有点麻烦。我已经安装了Mysql连接器dot net ver 8.0.12。我可以从phpmyadmin和mysql工作台访问数据库。所以我做了一个简单的代码，使用C＃程序连接数据库。这是我的代码：

using System;
using System.Windows.Forms;
using MySql.Data.MySqlClient;

namespace TryMySQL
{
    public partial class Form1 : Form
    {
        private MySqlConnection connection;
        private string server;
        private string port;
        private string database;
        private string uid;
        private string password;

        public Form1()
        {
            InitializeComponent();
            try
            {
                Initialize();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void Initialize()
        {
            server = "127.0.0.1";
            port = "3306";
            database = "testdb";
            uid = "root";
            password = "123456789";
            string connectionString;
            connectionString = "datasource=" + server + ";" + "port=" + port + ";" + "database=" +
            database + ";" + "username=" + uid + ";" + "password=" + password + ";";

            connection = new MySqlConnection(connectionString);
        }

        //open connection to database
        private bool OpenConnection()
        {
            try
            {
                connection.Open();
                return true;
            }
            catch (MySqlException ex)
            {
                //When handling errors, you can your application's response based 
                //on the error number.
                //The two most common error numbers when connecting are as follows:
                //0: Cannot connect to server.
                //1045: Invalid user name and/or password.
                switch (ex.Number)
                {
                    case 0:
                        MessageBox.Show("Cannot connect to server.  Contact administrator");
                        break;

                    case 1045:
                        MessageBox.Show("Invalid username/password, please try again");
                        break;
                }
                return false;
            }
        }
    }
}

但是当我执行程序时，它给出了以下结果：

我怎么了？我认为我只是做正确的事。对于这种情况，需要更多建议。