如何在Unity中实例化自定义类的GameObject？

Question

我有一个名为

GamePiece

的脚本，它附在预制件上。现在我想从包含所有预制件的

GamePiece[] gamePieces

中生成随机游戏片段。

    private IEnumerator SpawningRandomObjects()
    {
        Debug.Log("in SpawningRandomObjects");
        yield return new WaitForSeconds(Random.Range(2f, waitSpawnTime));
        Vector3 randomPosition = RandomPosition();

        GamePiece spawned = Instantiate<GamePiece>(RandomGamePiece(gamePieces), randomPosition, Quaternion.identity);

        Debug.Log("second to last line in SpawningRandomObjects"); //never comes to this line
        //yield return new WaitUntil(() => drinkRef.FreezeSpawn());
    }

    private GamePiece RandomGamePiece(GamePiece[] gamePieces)
    {
        return gamePieces[Random.Range(0, gamePieces.Length)];
    }

我不太明白如何在游戏中实例化它们，因为

Instantiate()

抛出以下错误：

InvalidCastException: Unable to cast object of type 'GameObject' to type 'GamePiece'.
  at UnityEngine.Object.Instantiate[T] (T original, UnityEngine.Vector3 position, UnityEngine.Quaternion rotation) [0x00000] in <00000000000000000000000000000000>:0 
  at SpawnObjects+<SpawningRandomObjects>d__16.MoveNext () [0x00000] in <00000000000000000000000000000000>:0 
  at UnityEngine.SetupCoroutine.InvokeMoveNext (System.Collections.IEnumerator enumerator, System.IntPtr returnValueAddress) [0x00000] in <00000000000000000000000000000000>:0 

Answer 1

错误是因为当您调用

Instantiate

而不是对象时，您传递的是附加到预制件的脚本组件。请从 Unity 的官方文档中阅读有关Instatiate的更多信息。

现在要修复您的错误，您需要引用您的 Prefab 并将其传递给

Instatiate

方法。要做到这一点，而不是拥有一个数组

GamePiece[] gamePieces

，您必须将其更改为这个

GameObject[] gamePieces

并添加所有预制件。如果您只有 1 个预制件，则不需要任何数组或列表，您可以直接使用单个引用。

应该是这样的：

GameObject spawned = Instantiate<GameObject>("ReplaceWithPrefabReference", randomPosition, Quaternion.identity);

Answer 2

Instantiate()

返回一个

gameobject

，而不是你的组件。它将复制您的组件所附加的游戏对象（这是您想要的），因为如果不附加到组件就无法存在

gameobjects

如果你只想要组件，那么只需在新的

GetComponent

上调用

gameobject

 GamePiece spawned = Instantiate<GamePiece>(RandomGamePiece(gamePieces), randomPosition, Quaternion.identity).GetComponent<GamePeice>();