通过遍历控件的Controls集合，判断遍历到的控件是不是单选按钮类型。

老师，遍历时读取不到Radiobutton选定的值，还请老师指点。

private void Form1_Load(object sender, EventArgs e)
        {
            //List<string> list = new List<string>();
            //foreach(var item in this.Controls)
            //{
            //    if(item is RadioButton)
            //    {
            //        RadioButton rb = item as RadioButton;
            //        if (rb.Checked)
            //            list.Add(rb.Text);
            //    }
            //}
            ////label2.Text = list[1];
            //foreach(var i in list)
            //{
            //    label1.Text += i;
            //}