Unity/EditorWindow/GameObjectをPrefabに変更

全シーンの、指定したGameObjectをPrefabに変更するコード

using UnityEditor;
using UnityEngine;
using UnityEditor.SceneManagement;
using UnityEngine.SceneManagement;
using System.IO;

public class ReplaceObjectWithPrefab : EditorWindow
{
    private string directoryPath = "Assets/Scenes";
    private string objectName = "ReturnButton";
    private GameObject prefab;

    [MenuItem("Tools/Replace Object With Prefab")]
    public static void ShowWindow()
    {
        GetWindow<ReplaceObjectWithPrefab>("Replace Object With Prefab");
    }

    private void OnGUI()
    {
        GUILayout.Label("Directory and Object Settings", EditorStyles.boldLabel);

        directoryPath = EditorGUILayout.TextField("Directory Path", directoryPath);
        objectName = EditorGUILayout.TextField("Object Name", objectName);
        prefab = (GameObject)EditorGUILayout.ObjectField("Prefab", prefab, typeof(GameObject), false);

        if (GUILayout.Button("Replace Objects in Scenes"))
        {
            ReplaceObjectsInScenes();
        }
    }

    private void ReplaceObjectsInScenes()
    {
        if (string.IsNullOrEmpty(directoryPath) || string.IsNullOrEmpty(objectName) || prefab == null)
        {
            Debug.LogError("Please specify the directory path, object name, and prefab.");
            return;
        }

        // ディレクトリ内のすべてのシーンファイルを取得
        string[] sceneFiles = Directory.GetFiles(directoryPath, "*.unity", SearchOption.AllDirectories);

        foreach (string scenePath in sceneFiles)
        {
            // シーンを開く
            Scene scene = EditorSceneManager.OpenScene(scenePath);

            if (!scene.IsValid())
            {
                Debug.LogError($"Invalid scene path: {scenePath}");
                continue;
            }

            // オブジェクトを探す
            GameObject targetObject = GameObject.Find(objectName);

            if (targetObject == null)
            {
                Debug.LogWarning($"Object '{objectName}' not found in scene: {scenePath}");
                continue;
            }

            // オブジェクトをプレハブに置き換える
            GameObject newObject = (GameObject)PrefabUtility.InstantiatePrefab(prefab, scene);
            newObject.transform.position = targetObject.transform.position;
            newObject.transform.rotation = targetObject.transform.rotation;

            // 旧オブジェクトを削除
            DestroyImmediate(targetObject);

            // シーンを保存する
            EditorSceneManager.MarkSceneDirty(scene);
            EditorSceneManager.SaveScene(scene);

            Debug.Log($"Object replaced successfully in scene: {scenePath}");
        }
    }
}