GridView 全选问题

前台： <asp:TemplateField HeaderText="全选"> <HeaderTemplate> <asp:CheckBox ID="CheckBox2" runat="server"  Text="全选" OnCheckedChanged="aa" /> </HeaderTemplate> <ItemTemplate> <asp:CheckBox ID="CheckBox1" runat="server"  /> </ItemTemplate> </asp:TemplateField> 后台： public void aa(object sender, System.EventArgs ea) { CheckBox cb = (CheckBox)sender; if (cb.Text == "全选") { foreach (GridViewRow gv in this.GridView1.Rows) { CheckBox cd = (CheckBox)gv.FindControl("CheckBox1"); cd.Checked = cb.Checked; cb.Text = "反选"; } } else { cb.Text = "反选"; foreach (GridViewRow gv in this.GridView1.Rows) { CheckBox cd = (CheckBox)gv.FindControl("CheckBox1"); cd.Checked = cb.Checked; cb.Text = "全选"; } } }