EditorUtility.ReplacePrefab 替换预置

// Creates a prefab from the selected GameObjects.
// if the prefab already exists it asks if you want to replace it
//从选择的游戏物体创建预置。
//如果预置已经存在，询问是否要替换
class CreatePrefabFromSelected extends ScriptableObject {

	@MenuItem("Examples/Create Prefab From Selected")
	static function CreatePrefab() {
		var objs = Selection.gameObjects;

		for (var go : GameObject in objs) {
			var localPath : String = "Assets/" + go.name + ".prefab";
			if (AssetDatabase.LoadAssetAtPath(localPath, GameObject)) {
				if (EditorUtility.DisplayDialog("Are you sure?",
					"The prefab already exists. Do you want to overwrite it?",
					"Yes",
					"No"))
					createNew(go, localPath);
			} else {
				createNew(go, localPath);
			}

		}
	}
	@MenuItem("Examples/Create Prefab From Selected", true)
	static function ValidateCreatePrefab() {
		return Selection.activeGameObject != null;
	}

	static function createNew(obj : GameObject, localPath : String) {
		var prefab : Object = EditorUtility.CreateEmptyPrefab(localPath);
		EditorUtility.ReplacePrefab(obj, prefab);
		AssetDatabase.Refresh();

		DestroyImmediate(obj);
		var clone : GameObject = EditorUtility.InstantiatePrefab(prefab) as GameObject;
	}
}