GridView1 footer求和

//
ShowFooter="True"
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[5].Text)
        }
        if (e.Row.RowIndex >= 0)
        {
            sum += Convert.ToDouble(e.Row.Cells[5].Text);
        }
        else if (e.Row.RowType == DataControlRowType.Footer)
        {
            e.Row.Cells[4].Text = "总价格为：";
            e.Row.Cells[5].Text = sum.ToString();
            e.Row.Cells[2].Text = "平均价格为：";
            e.Row.Cells[3].Text = ((int)(sum /          GridView1.Rows.Count)).ToString();
        }
    }

 1、先在顶部声明公共变量
 private float production_Cost = 0;
 2、然后将Gridview的【ShowFooter】属性设置为【true】。
 3、再在Gridview的【RowDataBound】事件中写道：

protected void Gridview_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        DataRowView drv = (DataRowView)e.Row.DataItem;
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            production_Cost += float.Parse(drv["totalCosts"].ToString());
        }
        if (e.Row.RowType == DataControlRowType.Footer)
        {
            e.Row.Cells[11].Text = "小計:";
            //e.Row.Cells[12].Text = Math.Round(production_Cost, 5).ToString();
            e.Row.Cells[12].Text = production_Cost.ToString();
        }
    }

if(e.Row.RowType==DataControlRowType.Footer)
{
    GridViewRow headrow = GridView1.HeaderRow;
    GridViewRow footerrow = GridView1.FooterRow;
for (int j = 0; j < headrow.Cells.Count - 1; j++)
                {
                    string headfield = headrow.Cells[j].Text;
                    foreach (string b in All_Field)
                    {
                        if (headfield.Contains(b))
                        {
                            string sumnum = dssumresult.Tables[0].Rows[0][headfield].ToString();
                            footerrow.Cells[j].Text = sumnum;
                        }
                    }
                }
}

    protected void Button1_Click(object sender, EventArgs e)
    {
        decimal dsum =0;
        for (int i = 0; i < GridView1.HeaderRow.Cells.Count; i++)
        {
            if (GridView1.HeaderRow.Cells[i].Text.IndexOf("(N)")>-1)
            {
                for (int j = 0; j < GridView1.Rows.Count; j++)
			    {
			        dsum += Convert.ToDecimal(GridView1.Rows[j].Cells[i].Text.Trim());
			    }
                GridView1.FooterRow.Cells[i].Text = dsum.ToString();
            }

            //if (GridView1.Rows[i].RowType == DataControlRowType.DataRow)
            //{
            //    string name = GridView1.Rows[i].Cells[0].Text;//获取第i行第1列的内容
            //    TextBox txtID = (TextBox)GridView1.Rows[i].Cells[1].FindControl("textBox");
            //    string ID = txtID.Text; //获取TextBox里的内容
            //}
        }
    }

 //创建DataTable
    protected DataTable CreateDT()
    {
        DataTable tblDatas = new DataTable("Datas");
        //序号列
        //tblDatas.Columns.Add("ID", Type.GetType("System.Int32"));
        //tblDatas.Columns[0].AutoIncrement = true;
        //tblDatas.Columns[0].AutoIncrementSeed = 1;
        //tblDatas.Columns[0].AutoIncrementStep = 1;
        //数据列
        tblDatas.Columns.Add("身份证号码", Type.GetType("System.String"));
        tblDatas.Columns.Add("姓名", Type.GetType("System.String"));
        tblDatas.Columns.Add("出生日期", Type.GetType("System.String"));
        tblDatas.Columns.Add("性别", Type.GetType("System.String"));
        tblDatas.Columns.Add("基本工资", Type.GetType("System.Decimal"));
        tblDatas.Columns.Add("奖金", Type.GetType("System.Decimal"));
        //统计列开始
        tblDatas.Columns.Add("应发合计", Type.GetType("System.String"), "基本工资+奖金");
        //统计列结束
        tblDatas.Columns.Add("家庭住址", Type.GetType("System.String"));
        tblDatas.Columns.Add("邮政编码", Type.GetType("System.String"));

        tblDatas.Rows.Add(new object[] { null, "张三", "1982", "0", 3000, 1000, null, "深圳市", "518000" });
        tblDatas.Rows.Add(new object[] { null, "李四", "1983", "1", 3500, 1200, null, "深圳市", "518000" });
        tblDatas.Rows.Add(new object[] { null, "王五", "1984", "1", 4000, 1300, null, "深圳市", "518000" });
        tblDatas.Rows.Add(new object[] { null, "赵六", "1985", "0", 5000, 1400, null, "深圳市", "518000" });
        tblDatas.Rows.Add(new object[] { null, "牛七", "1986", "1", 6000, 1500, null, "深圳市", "518000" });
        return tblDatas;
    }

    //转换DataTable中的数据 用于逻辑处理相应的数据 显示
    protected DataTable FormatDT()
    {
        DataTable dt1 = CreateDT();
        //容错处理 用于不确定 自动产生的列
        if (dt1.Columns.Contains("性别"))
        {
            foreach (DataRow dr in dt1.Rows)
            {
                dr["性别"] = (dr["性别"].ToString() == "0") ? "女" : "男";
            }
        }
        return dt1;
    }

 /// <summary>
    /// 将DT转换为Execl的方法
    /// </summary>
    /// <param name="dt">需要导出的DT
    /// <param name="page">页面
    /// <param name="fileName">文件名
    public void ToExecl(DataTable dt, Page page, string fileName)
    {
        HttpResponse response = page.Response;
        response.Clear();
        response.ContentType = "application/x-excel";
        response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
        response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8) + ".xls");
        StringBuilder sB = new StringBuilder();
        for (int j = 0; j < dt.Columns.Count; j++)
        {
            sB.Append(dt.Columns[j].Caption + "\t");
        }
        sB.Append("\n");
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            for (int k = 0; k < dt.Columns.Count; k++)
            {
                sB.Append("=\"" + dt.Rows[i][k].ToString() + "\"\t"); //解决导出的单元格以科学计数法显示的问题
            }
            sB.Append("\n");
        }
        response.Write(sB.ToString());
        response.End();
    }
public void ToWord(DataTable dt, Page page, string filName)
   {
       HttpResponse response = page.Response;
       response.Clear();
       response.ContentType = "application/msword";
       response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
       response.AddHeader("Content-Disposition","attachment:filename="+System.Web.HttpUtility.UrlEncode(filName,System.Text.Encoding.UTF8)+".doc");
       StringBuilder sBuilder = new StringBuilder();
       for (int i = 0; i < dt.Rows.Count; i++)
       {
           sBuilder.Append(dt.Rows[i][1].ToString()+"\n");
       }
       response.Write(sBuilder.ToString());
       response.End();
   }  

public void ToXML(DataTable dt, Page page, string filename)
{
    HttpResponse response = page.Response;
    //DataSet ds = new DataSet();
    response.Clear();
    response.ContentType = "application/x-excel";
    response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
    response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(filename,System.Text.Encoding.UTF8) + ".xls");
    System.Text.UTF8Encoding utf8 = new System.Text.UTF8Encoding();
    System.Xml.XmlTextWriter xw = new XmlTextWriter(response.OutputStream, utf8);
    xw.Formatting = Formatting.Indented;
    xw.Indentation = 4;
    xw.IndentChar = ' ';
    dt.TableName = "dd";
    dt.WriteXml(xw);
    dt = null;
    GC.Collect();
    xw.Flush();
    xw.Close();
    response.End();
}  

  foreach (GridViewRow gvr in GridView1.Rows)
        {
            foreach (TableCell gvCell in gvr.Cells)
            {
                //gvCell就是你想要的列了
            }
        }