如下程式碼，我在關閉窗體是把RadioButton的當前索引值存到ini檔案中

 　　　　　　 ridioButtonIndex = 0;
            foreach (Control con in groupBoxClear.Controls)
            {
                if (con is RadioButton)
                {
                    if ((con as RadioButton).Checked)
                    {
                        
 
break;
                    }
                    ridioButtonIndex++;
                }
            }
            Ini.IniWriteValue("清除檔案", "day", ridioButtonIndex.ToString());

然後在窗體初始化時再讀出來並解析索引

//讀取儲存天數索引
            string deleteDay = Ini.IniReadValue("清除檔案", "day");
            switch (deleteDay)
            {
                
 
case "4":
                    radioButtonNot.Select();
                    break;
                case "3":
                    radioButtonDay3.Select();
                    break;
                case "2":
                    radioButtonDay7.Select();
                    break;
                case
 
 "1":
                    radioButtonDay15.Select();
                    break;
                case "0":
                    radioButtonDay30.Select();
                    break;
                default:
                    break;
            }

窗體如下