C# 基于按键更新字符串

我希望这不是一个愚蠢的问题，但我想不出来

我有一门赤骨游戏课：

public class Game1 : Game
{
    GraphicsDeviceManager graphics;
    SpriteBatch spriteBatch;
    String inputHolder;

    public Game1()
        : base()
    {
        graphics = new GraphicsDeviceManager(this);
        Content.RootDirectory = "Content";

        inputHolder = "Enter your keys: ";
    }

    protected override void Initialize()
    {
        base.Initialize();


        InputManager.stringToUpdate = inputHolder;

    }
    protected override void LoadContent()
    {
        spriteBatch = new SpriteBatch(GraphicsDevice);
    }

    protected override void UnloadContent()
    {
    }

    protected override void Update(GameTime gameTime)
    {
        if (Keyboard.GetState().IsKeyDown(Keys.Escape))
        {
            Exit();
        }
        base.Update(gameTime);

        InputManager.update(Keyboard.GetState());
    }

    protected override void Draw(GameTime gameTime)
    {
        GraphicsDevice.Clear(Color.CornflowerBlue);

        base.Draw(gameTime);

        Console.WriteLine(inputHolder);
    }
}

我还有一个InputManager类：

static class InputManager
{
    public static string stringToUpdate;

    public static void update(KeyboardState kbState)
    {
        if (stringToUpdate != null)
        {
            foreach (Keys k in kbState.GetPressedKeys())
            {
                stringToUpdate += k.ToString();
            }
        }
    }
}

但是，无论我按什么键，原始字符串inputHolder都不会受到影响，即使字符串在C#中被视为引用类型

我试过换衣服 InputManager.stringToUpdate=inputHolder； 到 InputManager.stringToUpdate=ref inputHolder； 什么也没发生

---

我在这里遗漏了什么？

正如前面所说，字符串是不可变的。在类中包装inputHolder字符串将获得所需的效果：

public class InputHolder
{
    public string Input { get; set; }
}

public class Game1 : Game
{
    GraphicsDeviceManager graphics;
    SpriteBatch spriteBatch;
    InputHolder inputHolder = new InputHolder();

    public Game1()
        : base()
    {
        graphics = new GraphicsDeviceManager(this);
        Content.RootDirectory = "Content";

        inputHolder.Input = "Enter your keys: ";
    }

    protected override void Initialize()
    {
        base.Initialize();
        InputManager.inputHolderToUpdate = inputHolder;
    }

    // etc

    protected override void Draw(GameTime gameTime)
    {
        GraphicsDevice.Clear(Color.CornflowerBlue);
        base.Draw(gameTime);
        Console.WriteLine(inputHolder.Input);
    }
} 

static class InputManager
{
    public static InputHolder inputHolderToUpdate;

    public static void update(KeyboardState kbState)
    {
        if (inputHolderToUpdate != null)
        {
            foreach (Keys k in kbState.GetPressedKeys())
            {
                inputHolderToUpdate.Input = inputHolderToUpdate.Input + k.ToString();
            }
        }
    }
}

---

字符串是不可变的。传递字符串时，传递的是对其内容的引用，而不是“指向内容指针的指针”。您需要对

inputHolder

引用的引用才能对其进行更新。但你不能。看看这个：