在winform中方格gropbox,gropbox中放几个CheckBox空间，然后text分别是星期一到星期日。
string czsj = "";
            foreach (Control c in groupBox3.Controls)
            {
                if (c is CheckBox)
                {
                    CheckBox cb = c as CheckBox;
                    if (cb.Checked == true)
                    {
                        if (czsj == "")
                        {
                            czsj += cb.Text;
                        }
                        else
                        {
                            czsj += "，" + cb.Text;
                        }
                    }
                }
            }
我用这种遍历法，得到的结果，并不是从星期一到星期日的顺序。请问，我如何做才能使得到的结果是按照顺序排列的（比如：“星期一，星期四”之类的）？