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>