C# Can';t描述不同类中两个对象之间的冲突以添加健康栏
我正在尝试将健康栏添加到我的2d平台。Atm我试图定义两个物体(火箭和玩家)之间的碰撞,但我不知道如何引用/使用它们。我已将错误作为注释写入代码中 这是健康课程:C# Can';t描述不同类中两个对象之间的冲突以添加健康栏,c#,object,xna,collision,C#,Object,Xna,Collision,我正在尝试将健康栏添加到我的2d平台。Atm我试图定义两个物体(火箭和玩家)之间的碰撞,但我不知道如何引用/使用它们。我已将错误作为注释写入代码中 这是健康课程: using Microsoft.Xna.Framework; class Health : GameObjectList { public Health(int layer = 3, string id = "") : base(layer, id) { for(int i = 0; i < 255; i+=85)
using Microsoft.Xna.Framework;
class Health : GameObjectList
{
public Health(int layer = 3, string id = "") : base(layer, id)
{
for(int i = 0; i < 255; i+=85)
if(i % 85 == 0)
{
SpriteGameObject health = new SpriteGameObject("Sprites/spr_health", 3);
health.Position = new Vector2(120 + i, 15);
this.Add(health);
}
}
public override void Update(GameTime gameTime)
{
base.Update(gameTime);
Player player = GameWorld.Find("player") as Player;
Rocket rocket = GameWorld.Find("rocket") as Rocket;
foreach (GameObject obj in gameObjects)
{
SpriteGameObject h = obj as SpriteGameObject;
if (rocket.CollidesWith(player))
//This is wat it says as an error:
//An unhandled exception of type 'System.NullReferenceException' occurred in TickTick.exe
//Additional information: Object reference not set to an instance of an object.
{
this.Remove(h);
return;
}
}
}
}
这是游戏世界的查找方法:
public GameObject Find(string id)
{
foreach (GameObject obj in gameObjects)
{
if (obj.ID == id)
return obj;
if (obj is GameObjectList)
{
GameObjectList objlist = obj as GameObjectList;
GameObject subobj = objlist.Find(id);
if (subobj != null)
return subobj;
}
}
return null;
}
火箭级:
using Microsoft.Xna.Framework;
class Rocket : AnimatedGameObject
{
protected double spawnTime;
protected Vector2 startPosition;
public Rocket(bool moveToLeft, Vector2 startPosition)
{
this.LoadAnimation("Sprites/Rocket/spr_rocket@3", "default", true, 0.2f);
this.PlayAnimation("default");
this.Mirror = moveToLeft;
this.startPosition = startPosition;
Reset();
}
public override void Reset()
{
this.Visible = false;
this.position = startPosition;
this.velocity = Vector2.Zero;
this.spawnTime = GameEnvironment.Random.NextDouble() * 5;
}
public override void Update(GameTime gameTime)
{
base.Update(gameTime);
if (spawnTime > 0)
{
spawnTime -= gameTime.ElapsedGameTime.TotalSeconds;
return;
}
this.Visible = true;
this.velocity.X = 600;
if (Mirror)
this.velocity.X *= -1f;
CheckPlayerCollision();
// check if we are outside the screen
Rectangle screenBox = new Rectangle(0, 0, GameEnvironment.Screen.X, GameEnvironment.Screen.Y);
if (!screenBox.Intersects(this.BoundingBox))
this.Reset();
}
public void CheckPlayerCollision()
{
Player player = GameWorld.Find("player") as Player;
if (this.CollidesWith(player) && this.Visible)
player.Die(false);
// CURRENTLY DON'T WANT THIS TO HAPPEN BECAUSE OF HEALTH BAR
}
}
我只是不知道如何才能让它发挥作用,将生命值降低1,最终让玩家在没有生命值的情况下死亡。我觉得这两条线中的一条或两条都是正确的
Player player = GameWorld.Find("player") as Player;
Rocket rocket = GameWorld.Find("rocket") as Rocket;
返回null,执行该检查,确保gameObjects列表包含您要查找的内容,并且它们是您期望的类型
即使你的玩家死了,你也要检查,在它给你带来错误的代码部分之前,你就把它从世界上移除了,也许在你检查的时候,玩家(或火箭)已经从世界上移除了我该如何检查列表?在你的Find方法中设置一个断点,并检查gameObjects的值
Player player = GameWorld.Find("player") as Player;
Rocket rocket = GameWorld.Find("rocket") as Rocket;