概要

using UnityEditor;
using UnityEditor.SceneManagement;
using UnityEngine;
using UnityEngine.Tilemaps;

[CustomEditor(typeof(Tilemap))]
public sealed class TilemapEditor : Editor
{
    public override void OnInspectorGUI()
    {
        base.OnInspectorGUI();

        var tilemap = target as Tilemap;

        if ( GUILayout.Button( "Refresh All Tiles" ) )
        {
            tilemap.RefreshAllTiles();
            EditorSceneManager.MarkSceneDirty( tilemap.gameObject.scene );
        }
    }
}