c# XNA不一致的可访问性

这一定是一些非常简单的东西，我没有得到，但这里是我的代码:

    public class Game1 : Microsoft.Xna.Framework.Game
{
    GraphicsDeviceManager graphics;
    SpriteBatch spriteBatch;        
    WorldManager worldManager;
    Player m_player = new Player(new Point(30, 15));
    protected override void Initialize()
    {
        worldManager = new WorldManager(this, m_player);
        Components.Add(worldManager);
        base.Initialize();
    }

…

现在在WorldManage:

public class WorldManager : Microsoft.Xna.Framework.DrawableGameComponent
{
    SpriteBatch spriteBatch;
    //UserControlledTile player;
    Player player;
    List<Tile> tileList = new List<Tile>();
    World world;
    SpriteFont testFont;
    public WorldManager(Game game, Player player)
        : base(game)
    {
        this.player = player;
        world = new World();            
    }

我得到这个错误:

Error   1   Inconsistent accessibility: parameter type 'WindowsGame2.Player' is less accessible than method 'WindowsGame2.WorldManager.WorldManager(Microsoft.Xna.Framework.Game, WindowsGame2.Player)' D:'dropbox'Dropbox'Projects'WindowsGame2'WindowsGame2'WindowsGame2'WorldManager.cs  28  16  WindowsGame2

这里是Player类:

class Player : Character
{
    public Player(Point startLoc)            
    {
        base.Position = startLoc;
        base.CharacterTile = new UserControlledTile(new Point(20, 15), Color.Yellow, "X");
        base.Name = "Hero";
        base.Attack = 1;
        base.Defense = 1;
        base.HP = 20;
        base.Level = 1;            
    } //end constructor
    public override void Update(GameTime gameTime)
    {
        //player has already moved
        if (hasMoved)
        {
            prevGameTime += gameTime.ElapsedGameTime.Milliseconds;
            if (prevGameTime > timeBetweenMove)
            {
                hasMoved = false;
                prevGameTime = 0;
            }
            return;
        }
        KeyboardState keyboardState = Keyboard.GetState();
        if (keyboardState.IsKeyDown(Keys.Left))
        {
            m_position.X--;
            hasMoved = true;
        }
        else if (keyboardState.IsKeyDown(Keys.Right))
        {
            m_position.X++;
            hasMoved = true;
        }
        else if (keyboardState.IsKeyDown(Keys.Up))
        {
            m_position.Y--;
            hasMoved = true;
        }
        else if (keyboardState.IsKeyDown(Keys.Down))
        {
            m_position.Y++;
            hasMoved = true;
        }
        if (m_position.X < 0)
            m_position.X = 0;
        if (m_position.X > 56)
            m_position.X = 56;
        if (m_position.Y < 0)
            m_position.Y = 0;
        if (m_position.Y > 32)
            m_position.Y = 32;

        m_CharacterTile.Update(gameTime, m_position);
    }
    public override void Draw(GameTime gameTime, SpriteBatch spriteBatch, SpriteFont font)
    {
        m_CharacterTile.Draw(gameTime, spriteBatch, font);
    }

}//end class

我还在学习c#，但它似乎来自Java，我不明白是什么导致这个问题…