private void OnAddProjectButtonClick() { var p = MProject.CreateInstance <MProject>(); p.name = Guid.NewGuid().ToString(); p.ProjectName = "Project " + (this.sceneContainer.projects.Count + 1); AssetDatabase.AddObjectToAsset(p, this.sceneContainer); this.sceneContainer.projects.Add(p); EditorUtility.SetDirty(this.sceneContainer); AssetDatabase.SaveAssets(); projectList.selectedIndex = this.sceneContainer.projects.Count - 1; }