c#动态添加CheckBox(全选及判断是否选中)

<div>
<asp:CheckBox ID="cbAll" runat="server" AutoPostBack="True" OnCheckedChanged="cbAll_CheckedChanged" Text="全选 " />
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" /><br />
</div>

aspx.cs：

Page_Load：

　　//动态添加CheckBox

 　　int j = 5;

        for (int i = 1; i <= j; i++)
        {
            CheckBox cb = new CheckBox();
            cb.Text = i.ToString();
            cb.Font.Size = System.Web.UI.WebControls.FontUnit.Small;
            cb.ID = "cb" + i.ToString();
            cb.Checked = false;
            Page.Form.Controls.Add(cb);
        }

　//全选及取消
    protected void cbAll_CheckedChanged(object sender, EventArgs e)
    {
        CheckBox all = sender as CheckBox;
        foreach (Control ctl in Page.Form.Controls)
        {
            if (ctl is CheckBox)
            {
                CheckBox chk = ctl as CheckBox;
                chk.Checked = all.Checked;
            }
        }
    }

　 //获取选中的除全选外
    protected void Button1_Click(object sender, EventArgs e)
    {       
        foreach (Control ctl in Page.Form.Controls)
        {
            if (ctl is CheckBox)
            {
                CheckBox chk = ctl as CheckBox;
                if (chk.Checked == true && chk.Text.Trim() != "全选")
                {
                    Response.Write(chk.Text);
                }
            }
        }
    }