foreach (Control c in Page.Controls)
            {
                if (c.GetType().ToString() == "System.Web.UI.WebControls.RadioButton")
                    ((RadioButton)c).Enabled = false;
            }

------解决方案--------------------
2楼的应该没错,不过代码写法有点不好,
C# code
//if (c.GetType().ToString() == "System.Web.UI.WebControls.RadioButton")
//改为
if (c.GetType() == typeof(RadioButton))

------解决方案--------------------
C# code

//page只是一个节点.你的Radiobutton可能是在page.form节点下.所有在不确定节点是哪个的情况下最好循环遍历一下.

public void SetRadioButton(Control obj)
{
    for(int i=0;i<obj.Controls.Count;i++)
       {
            if(obj.Controls[i].Count>0)
                 SetRadioButton(obj.Controls[i];
            else
            {
                 if(obj.Controls[i].GetType==typeof(RadioButton))
                     ((RadioButton)obj.Controls[i]).Enabled = false;
            }
       }
}

protected void Page_Load(object sender, EventArgs e)
{
   SetRadioButton(Page);
}

------解决方案--------------------
    protected void Page_Load(object sender, EventArgs e)
   {
       SetRadioButton(this.Page);
   }

   public void SetRadioButton(Control obj)
   {
       for (int i = 0; i < obj.Controls.Count; i++)
       {
           if (obj.Controls[i].Controls.Count > 0)
               SetRadioButton(obj.Controls[i]);
           else
           {
               if (obj.Controls[i].GetType() == typeof(RadioButton))
                   ((RadioButton)obj.Controls[i]).Enabled = false;
           }
       }
   }