CommandText属性没有被正确初始化(MySqlDataReader)

读者总是null，我不知道为什么。

在一个方法连接之前，一切正常。

代码:

private MySqlConnection connection;
private MySqlCommand command;
private MySqlDataReader Reader;
public Form1()
{
    InitializeComponent();
    DBint();
}
private void DBint()
{
    string myConnectionString = "SERVER=xxx;PORT=3306;" +
                                "DATABASE=xxx;" +
                                "UID=root;" +
                                "PASSWORD=xxx;";
    connection = new MySqlConnection(myConnectionString);
    command = connection.CreateCommand();
    MySqlDataReader Reader;//error occures her
    connection.Open();
    Reader = command.ExecuteReader();               
    //MessageBox.Show(tmp);                
    //connection.Close();    
}