Question

*编辑* ::我在收集实际代码时发现了问题。

我正在Visual Studio 2015中使用C＃

我无法传递具有类型为class object的字段的类对象。我创建了两个简单的类，即A类和B类，并且A类中有一个类型为B类的字段。创建了A类的实例，然后将其类型为B类的字段设置为B类的新实例后，似乎工作正常。但是，当我将类A的实例传递给方法时，类型B的字段显示为Null。我可以编写所有B类字段的值，并且它们在调试之前会在进入方法之前显示正确的值，但是当将A类对象传递给方法时，它将引发NullReferenceException并告诉我“对象引用未设置为实例”一个物体。”我的A类对象中的所有其他字段都可以正常工作； B类类型的字段是唯一执行此操作的字段。

当我将方法复制/粘贴到新的解决方案并进行修剪/添加以消除所有错误时，它可以正常工作。因此，我不确定为什么我的程序会一直以这种方式失败。

有什么建议吗？

class Program
{

    // Start of the program
    static void Main(string[] args)
    {
        // Instantiate the player
        Player player = new Player() { playerWeapon = new Weapon() };

        showPlayerStats(player);
    }

    // Method shows the player's stats
    static void showPlayerStats(Player player)

    {
        Console.WriteLine(" ******** Player Statistics ********");
        Console.WriteLine();
        Console.WriteLine(" Player Name:".PadRight(16) + player.playerName);
        Console.WriteLine(" Player Gender:".PadRight(16) + player.playerGender);
        Console.WriteLine(" Player Race:".PadRight(16) + player.playerRace);
        Console.WriteLine(" Player Class:".PadRight(16) + player.playerClass);
        Console.WriteLine(" Player Health:".PadRight(16) + player.playerHealth + "/" + player.playerMaxHealth);
        Console.WriteLine(" Player EXP:".PadRight(16) + player.playerEXP);
        Console.WriteLine(" Player Gold:".PadRight(16) + player.playerMoney);
        Console.WriteLine(" Player Weapon:".PadRight(16) + player.playerWeapon.name);
        Console.ReadLine();
    }

    // Create player with random attributes
    static Player RandomPlayer()
    {
        Player player = new Player(); //<<== This is where I goofed
        return player;
    }
}
class Player
{
    public string playerName = "Name";
    public string playerGender = "Gender";
    public string playerRace = "Race";
    public string playerClass = "Class";
    public int playerHealth = 100;
    public int playerEXP = 0;
    public int playerMaxHealth = 100;
    public int playerMoney = 50;
    public double playerOneHanded = 1;
    public double playerTwoHanded = 1;
    public double playerRanged = 1;
    public double playerMagic = 1;
    public Weapon playerWeapon;
}

class Weapon
{
    public string name = "Knife";
    public int damage = 6;
    public string type = "One";
}

Answer 1

当我回顾代码以收集实际片段时，发现了问题。我在测试游戏时使用的是随机角色创建过程，而忽略了在返回玩家的方法之后将Weapon放到Player.playerWeapon字段中，因此使用了带有Null字段的Player对象的新实例。感谢您的协助。

不为null的对象在我的方法中显示为null

1 个答案: