Как вызвать функцию, когда действие выбрано для определенных записей в древовидной структуре

 private void Initialize()
    {
        server = "localhost";
        database = "connectcsharptomysql";
        uid = "username";
        password = "password";
        string connectionString;
        connectionString = "SERVER=" + server + ";" + "DATABASE=" + 
        database + ";" + "U`enter code here`ID=" + uid + ";" + "PASSWORD=" + password + ";";

        connection = new MySqlConnection(connectionString);
    }