GridView中加上CheckBox 的全选功能的代码

<asp:TemplateField>     
                    <HeaderTemplate>     
                        <asp:CheckBox ID="CheckAll" runat="server" onclick= "SelectAllCheckboxes(this);"  Text="全選/取消" ToolTip="按一次全選，再按一次取消全選" />     
                    </HeaderTemplate>     
                    <ItemTemplate>     
                        <asp:CheckBox ID="CheckBox2" runat="server" Text="全選"/>     
                    </ItemTemplate>     
</asp:TemplateField>

<script type="text/javascript">     
function SelectAllCheckboxes(spanChk)     
{     
    elm=document.forms[0];     

    for(i=0;i<elm.length;i++)     
        {     
            if(elm[i].type=="checkbox" && elm[i].id!=spanChk.id)     
            {     
                if(elm.elements[i].checked!=spanChk.checked)     
                 elm.elements[i].click();                     
            }     
    }     
}     
</script>

int i;     
for (i = 0; i < this.GridView1.Rows.Count; i++)     
{     
    if (((CheckBox)GridView1.Rows[i].FindControl("CheckBox2")).Checked)     
    {     
    Response.Write(GridView1.DataKeys[i].Value.ToString());     
    //GridView1.DataKeys[i].Value.ToString()可以抓到該列的DataKeys的值，我設定的是pk值     
    }     
}