asp.net下gridview 批量删除的实现方法

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false"> 
<Columns>     
        <asp:BoundField DataField="vote_id" HeaderText="编号" /> 
        <asp:BoundField DataField="vote_name" HeaderText="名称" />  
    <asp:TemplateField HeaderText="选择"> 
        <ItemTemplate> 
            <asp:CheckBox id="cbxId" runat="Server" /> 
        </ItemTemplate> 
    </asp:TemplateField> 
</Columns> 
</asp:GridView> 

//初始化数据 
private void dataInit() 
{ 
    string sqlText = "select * from vote"; 
    SqlConnection conn = getCon(); 
    SqlDataAdapter da = new SqlDataAdapter(sqlText,conn); 
    DataSet ds = new DataSet(); 
    conn.Open(); 
    da.Fill(ds, "vote"); 
    GridView1.DataSource = ds; 
    GridView1.DataKeyNames = new string[]{"vote_id"}; 
    GridView1.DataBind(); 
    conn.Close(); 
    conn.Dispose(); 
}