為模板列中的單選按鈕定閱事件

1.默認不能全是選中，否則，事件不觸發
2.單選為動態創建，所以必須在代碼中增加事件.

<asp:RadioButton id=rbItem runat="server" >


private void DataGridEx1_ItemCreated(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
		{
			if(e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
			{
				RadioButton cbIsDefault = (RadioButton)e.Item.Cells[4].FindControl("rbItem");//是否是缺省
				if(cbIsDefault!=null)
				{
					cbIsDefault.AutoPostBack=true;
					cbIsDefault.CheckedChanged+=new EventHandler(cbIsDefault_CheckedChanged);
				}
			}
		}

		private void cbIsDefault_CheckedChanged(object sender, EventArgs e)
		{
			if(!(sender is RadioButton)) return;			

			for(int i=0; i<DataGridEx1.Items.Count; i++)
			{
				RadioButton rbtn = (RadioButton)DataGridEx1.Items[i].FindControl("rbItem");
				rbtn.Checked = false;					
			}
			((RadioButton)sender).Checked=true;		

		}