unity editor模式下读取文件夹资源
string path = EditorUtility.OpenFolderPanel("Load png Textures", "", ""); //打开文件夹
string[] files = Directory.GetFiles(path); //获取所有文件路径
Object[] os = new Object[] { AssetDatabase.LoadAssetAtPath(f2, typeof(UnityEngine.Sprite)) }; //load 资源