Gridview中实现求和统计功能

GridView加入自动求和求平均值小计

效果图：
 
解决方案：    
private double sum = 0; //取指定列的数据和，你要根据具体情况对待可能你要处理的是int
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        
        if (e.Row.RowIndex >= 0)
        {
            sum += Convert.ToDouble(e.Row.Cells[6].Text);
        }
        else if (e.Row.RowType == DataControlRowType.Footer)
        {
            e.Row.Cells[5].Text = "总薪水为：";
            e.Row.Cells[6].Text = sum.ToString();
            e.Row.Cells[3].Text = "平均薪水为：";
            e.Row.Cells[4].Text = ((int)(sum / GridView1.Rows.Count)).ToString();
            
        }
    }
后台全部代码：
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.Drawing;
public partial class Default7 : System.Web.UI.Page
{
    SqlConnection sqlcon;
    SqlCommand sqlcom;
    string strCon = "Data Source=(local);Database=北风贸易;Uid=sa;Pwd=sa";
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            bind();
        }
    }
    protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
    {
        GridView1.EditIndex = e.NewEditIndex;
        bind();
    }
    protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        sqlcon = new SqlConnection(strCon);
        string sqlstr = "update 飞狐工作室 set 姓名='"
            + ((TextBox)(GridView1.Rows[e.RowIndex].Cells[1].Controls[0])).Text.ToString().Trim() + "',家庭住址='"
            + ((TextBox)(GridView1.Rows[e.RowIndex].Cells[3].Controls[0])).Text.ToString().Trim() + "' where 身份证号码='"
            + GridView1.DataKeys[e.RowIndex].Value.ToString() + "'";
        sqlcom = new SqlCommand(sqlstr, sqlcon);
        sqlcon.Open();
        sqlcom.ExecuteNonQuery();
        sqlcon.Close();
        GridView1.EditIndex = -1;
        bind();
    }
    protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
    {
        GridView1.EditIndex = -1;
        bind();
    }
    public void bind()
    {
        string sqlstr = "select top 5 * from 编程中国社区";
        sqlcon = new SqlConnection(strCon);
        SqlDataAdapter myda = new SqlDataAdapter(sqlstr, sqlcon);
        DataSet myds = new DataSet();
        sqlcon.Open();
        myda.Fill(myds, "编程中国社区");
        GridView1.DataSource = myds;
        GridView1.DataKeyNames = new string[] { "身份证号码" };
        GridView1.DataBind();
        sqlcon.Close();
    }
    private double sum = 0; //取指定列的数据和
    protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        
        if (e.Row.RowIndex >= 0)
        {
            sum += Convert.ToDouble(e.Row.Cells[6].Text);
        }
        else if (e.Row.RowType == DataControlRowType.Footer)
        {
            e.Row.Cells[5].Text = "总薪水为：";
            e.Row.Cells[6].Text = sum.ToString();
            e.Row.Cells[3].Text = "平均薪水为：";
            e.Row.Cells[4].Text = ((int)(sum / GridView1.Rows.Count)).ToString();
            
        }
    }
}
前台：唯一的花头就是设置ShowFooter="True" ，否则默认表头为隐藏的！
<asp:GridView ID="GridView1" runat="server"    AutoGenerateColumns="False" CellPadding="3"  OnRowEditing="GridView1_RowEditing"
                        OnRowUpdating="GridView1_RowUpdating" OnRowCancelingEdit="GridView1_RowCancelingEdit" BackColor="White" BorderColor="#CCCCCC" BorderStyle="None" BorderWidth="1px" Font-Size="12px" OnRowDataBound="GridView1_RowDataBound" ShowFooter="True"  >
                        <FooterStyle BackColor="White" ForeColor="#000066" />
                        <Columns>
                            <asp:CommandField HeaderText="编辑" ShowEditButton="True" />
                            <asp:BoundField DataField="身份证号码" HeaderText="编号" ReadOnly="True" />
                            <asp:BoundField DataField="姓名" HeaderText="姓名"  />
                            <asp:BoundField DataField="出生日期" HeaderText="邮政编码"  />
                            <asp:BoundField DataField="家庭住址" HeaderText="家庭住址"  />
                            <asp:BoundField DataField="邮政编码" HeaderText="邮政编码" />
                            <asp:BoundField DataField="起薪" HeaderText="起薪"  />
                           
                        </Columns>
                        <RowStyle ForeColor="#000066" />
                        <SelectedRowStyle BackColor="#669999" Font-Bold="True" ForeColor="White" />
                        <PagerStyle BackColor="White" ForeColor="#000066" HorizontalAlign="Left"  CssClass="ms-formlabel DataGridFixedHeader"/>
                        <HeaderStyle BackColor="#006699" Font-Bold="True" ForeColor="White" />
                    </asp:GridView>