簡單的物件池

下面是一個允許租用和返回給定物件型別的物件池示例。要建立物件池，需要使用 create 函式的 Func 和銷燬物件的 Action 來為使用者提供靈活性。在池為空時請求物件時，將建立一個新物件，並在請求池有物件時，然後從池中刪除物件並返回。

物件池

public class ResourcePool<T> where T : class
{
    private readonly List<T> objectPool = new List<T>();
    private readonly Action<T> cleanUpAction;
    private readonly Func<T> createAction;

    public ResourcePool(Action<T> cleanUpAction, Func<T> createAction)
    {
        this.cleanUpAction = cleanUpAction;
        this.createAction = createAction;
    }

    public void Return(T resource)
    {
        this.objectPool.Add(resource);
    }

    private void PurgeSingleResource()
    {
        var resource = this.Rent();
        this.cleanUpAction(resource);
    }

    public void TrimResourcesBy(int count)
    {
        count = Math.Min(count, this.objectPool.Count);
        for (int i = 0; i < count; i++)
        {
            this.PurgeSingleResource();
        }
    }

    public T Rent()
    {
        int count = this.objectPool.Count;
        if (count == 0)
        {
            Debug.Log("Creating new object.");
            return this.createAction();
        }
        else
        {
            Debug.Log("Retrieving existing object.");
            T resource = this.objectPool[count-1];
            this.objectPool.RemoveAt(count-1);
            return resource;
        }
    }
}

樣品用法

public class Test : MonoBehaviour
{
    private ResourcePool<GameObject> objectPool;

    [SerializeField]
    private GameObject enemyPrefab;

    void Start()
    {
        this.objectPool = new ResourcePool<GameObject>(Destroy,() => Instantiate(this.enemyPrefab) );
    }

    void Update()
    {
        // To get existing object or create new from pool
        var newEnemy = this.objectPool.Rent();
        // To return object to pool
        this.objectPool.Return(newEnemy);
        // In this example the message 'Creating new object' should only be seen on the frame call
        // after that the same object in the pool will be returned.
    }
}