public void Show() { var ret = Application.InputBox(Prompt, "範囲選択", Application.ActiveCell.get_Address(Microsoft.Office.Interop.Excel.XlReferenceStyle.xlA1), Type.Missing, Type.Missing, Type.Missing, Type.Missing, 8); IsCanceled = ret is bool; if (IsCanceled) { // ユーザがキャンセルボタンを選択した return; } Debug.Assert(ret is Microsoft.Office.Interop.Excel.Range); Data = ret; }