c# - 如何为按键拍摄添加延迟

Question

我正在制作太空射击游戏，我想知道如何延迟射击而不是乱按空格键，谢谢 :)

public void Shoot()
    {
        Bullets newBullet = new Bullets(Content.Load<Texture2D>("PlayerBullet"));
        newBullet.velocity = new Vector2((float)Math.Cos(rotation), (float)Math.Sin(rotation)) * 5f;
        newBullet.position = playerPosition + playerVelocity + newBullet.velocity * 5;
        newBullet.isVisible = true;

        if (bullets.Count() >= 0)
            bullets.Add(newBullet);
    }

Answer 1

我认为您想使用 XNA 的 GameTime 属性。每当你发射一颗子弹时，你应该记录它发生的时间作为当前的 GameTime.ElapsedGameTime 值。

这是一个TimeSpan，所以你可以像下面这样比较它:

// Create a readonly variable which specifies how often the user can shoot.  Could be moved to a game settings area
private static readonly TimeSpan ShootInterval = TimeSpan.FromSeconds(1);

// Keep track of when the user last shot.  Or null if they have never shot in the current session.
private TimeSpan? lastBulletShot;

protected override void Update(GameTime gameTime)
{
    if (???) // input logic for detecting the spacebar goes here
    {
        // if we got here it means the user is trying to shoot
        if (lastBulletShot == null || gameTime.ElapsedGameTime - (TimeSpan)lastBulletShot >= ShootInterval)
        {
            // Allow the user to shoot because he either has not shot before or it's been 1 second since the last shot.
            Shoot();
        }
    }
}