用js实现 全选功能（Gridview)

看效果：如下：

前台js：

<script language="javascript" type="text/javascript">
    var list = document.getElementsByName("ch");
    window.onload =function()
    {
        for(var i=0;i<list.length;i++)
        {
        list[i].onclick=chkclick;
        }
    }
    function chkclick()
    {
         var listVar="";
        for(var i=0;i<list.length;i++)
        {
            if(list[i].checked)
            {
             listVar+=list[i].value+",";
            }
        }
        document.getElementById("HiddenField1").value=listVar.subString(0,listVar.length-1);   
    }
    function allClick()
    {
         var c = document.getElementById("chk");
       
         if(c.checked)
         { 
             var listVar="";
         
             for(var i=0;i<list.length;i++)
             {
              list[i].checked=true;
              
              listVar+=list[i].value+",";
             }
            
             document.getElementById("HiddenField1").value=listVar;//.subString(0,listVar.length-1);   
      
         }
         else
         {
             for(var i=0;i<list.length;i++)
             { 
             list[i].checked=false;
             
             }
             document.getElementById("HiddenField1").value="";
         }
    }
    </script>

前台：

<asp:GridView ID="GridView1" AutoGenerateColumns="false" runat="server">
                <Columns>
                    <asp:TemplateField HeaderText="全选">
                        <ItemTemplate>
                            <input name="ch" value="<%#Eval("stu_No") %>" type="checkbox" />
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:BoundField DataField="stu_No" HeaderText="学号" />
                    <asp:BoundField DataField="stu_Name" HeaderText="姓名" />
                    <asp:BoundField DataField="stu_Sex" HeaderText="性别" />
                </Columns>
            </asp:GridView>
            <input id="chk" onclick="allClick()" type="checkbox" /><asp:HiddenField ID="HiddenField1"
                runat="server" />
            <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" /></div>

后台代码：

protected void Button1_Click(object sender, EventArgs e)
    {
        string s = this.HiddenField1.Value;
        string[] ss = s.Split(',');
        SqlConnection con = new SqlConnection(@"Data Source=.\sqlexpress;Initial Catalog=Northwind;Integrated Security=True");
       
        for (int i = 0; i < this.GridView1.Rows.Count; i++)
        {
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = con;
            cmd.CommandText = "delete from 高校学生信息表  where stu_No=@stu_No";
            SqlParameter sp = new SqlParameter("@stu_No",SqlDbType.NChar,10);
            sp.Value = ss[i];
            cmd.Parameters.Add(sp);
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
          
        }
        databind();
    }