c# - 如何在随机位置绘制单个 Sprite 10 次？

Question

我对此完全陌生，有一个问题。我在学校和家里都做过练习，但我不知道该怎么做。

问题是我想在屏幕上的 10 个随机位置绘制一个 Sprite ，而不使用特殊的 Sprite 类。我的问题是它们在绘制后又消失了。

解决了，感谢大家的帮助!

public class Game1 : Microsoft.Xna.Framework.Game
{
    GraphicsDeviceManager graphics;
    SpriteBatch spriteBatch;

    Texture2D turtleTexture;
    int counter = 0;
    Random randomera = new Random();
    int x;
    int y;

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

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

    /// <summary>
    /// </summary>
    protected override void LoadContent()
    {
        spriteBatch = new SpriteBatch(GraphicsDevice);
        turtleTexture = Content.Load<Texture2D>(@"Images/turtle_50x38");
    }

    protected override void UnloadContent()
    {
    }

    protected override void Update(GameTime gameTime)
    {
        if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
            this.Exit();

         /*
         if(counter < 10)
         {
             x = randomera.Next(600);
            y = randomera.Next(400);
            counter++;
         }
         */

        base.Update(gameTime);
    }

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

        spriteBatch.Begin(SpriteSortMode.FrontToBack, BlendState.AlphaBlend);


        if (counter < 10)
        {
            for (int i = 0; i < 10; i++)
            {
                spriteBatch.Draw(turtleTexture, new Vector2(randomera.Next(600), randomera.Next(400)),
                    Color.Black);
                counter++;
            }
        }

        spriteBatch.End();
        base.Draw(gameTime);
    }
}

Answer 1

如果你想让你的 Sprite 一直在相同的随机位置并且仍然清除你的视口(viewport)(例如，你可能想要渲染其他内容)你可以将每帧的随机种子重置为相同的值:

protected override void Draw(GameTime gameTime)
{
    randomera = new Random(seed);   
    GraphicsDevice.Clear(Color.White);

    spriteBatch.Begin(SpriteSortMode.FrontToBack, BlendState.AlphaBlend);


    if (counter < 10)
    {
        for (int i = 0; i < 10; i++)
        {
            spriteBatch.Draw(turtleTexture, new Vector2(randomera.Next(600), randomera.Next(400)),
                Color.Black);
            counter++;
        }
    }

    spriteBatch.End();
    base.Draw(gameTime);
}

种子应在您的 Initialize() 方法中随机生成，之后不得更改。

您也可以只使用预定义的坐标初始化列表:

List<Vector2> coords = Enumerable.Range(0, 10).Select(i => new Vector2(randomera.Next(600), randomera.Next(400)).ToList();

并在您的绘图例程中使用此列表:

for (int i = 0; i < 10; i++)
{
    spriteBatch.Draw(turtleTexture, coords[i],
        Color.Black);
}