Unity 中是否有 C# 函数来检测设定范围内的某种类型的游戏对象？

这很容易。您也可以按照 @BugFinder 的评论中的建议使用球体投射来实现它。但是，我建议使用简单的 GameObject.Find 方法。

首先，您应该制作一个玩家单行为并将其附加到所有玩家。

public class PlayerMono : MonoBehaviour
{
    // Implement you player code here
}

然后，在敌人的单一行为中 - 要找到最近的玩家，请添加以下代码。

public class EnemyMono : MonoBehaviour
{
    // Your custom code here...

    private PlayerMono[] allPlayers; // This list should be cached bcz it has a little bit of overhead which makes it non-feasible to be called everytime.

    private PlayerMono GetNearestPlayer(Vector3 enemyPosition)
    {
        if (allPlayers  == null)
        {
            allPlayers = GameObject.FindObjectsOfType<PlayerMono>();
            // otherwise do the following if you dont have a PlayerComponent and change PlayerMono references with GameObject
            // allPlayers = GameObject.FindGameObjectWithTag("PlayerTag");
        }

        // Make sure to not cache the following array as it will not take into account the updated positions of the Player.
        Vector3[] allPlayersPositions = allPlayers.Select(player => player.transform.position).ToArray();

        PlayerMono nearestPlayer = allPlayers[GetNearestPlayerIndex(transform.position, allPlayersPositions)];
        return nearestPlayer;
    }

    // You need to install the Burst Package for this. If it confuses you,
    // simply comment the [BurstCompile]. It won't have any effect on the result of the code.
    // I just tend to do this as a habit for such functions where i am looping over vectors or other such types.
    [BurstCompile]
    private int GetNearestPlayerIndex(Vector3 enemyPosition, Vector3[] allPlayersPositions)
    {
        Vector3 nearestPosition = Vector3.positiveInfinity;
        int nearestPlayerIndex = 0;

        int currentIndex = 0;

        foreach (var playerPosition in allPlayersPositions)
        {
            if (Vector3.Distance(enemyPosition, playerPosition) < nearestPosition.magnitude)
            {
                nearestPosition = playerPosition;
                nearestPlayerIndex = currentIndex;
            }

            currentIndex++;
        }

        return nearestPlayerIndex;
    }
}

现在你可以对最近的玩家做任何你想做的事情，比如：

PlayerMono nearestPlayer = GetNearestPlayer();
if (Vector3.Distance(transform.position, nearestPlayer.transform.position) <= 10f)
{
    AttackPlayer(nearestPlayer); // implement it according to your needs.
}
else
{
    JustRelax(); // Exhibit Idle behaviour
}