Gridview中加入求和和求平均值

 1 <asp:GridView ID="GridView1" ShowFooter="true" runat="server" AutoGenerateColumns ="false"  
 2             style="border:solid 1px black" onrowdatabound="GridView1_RowDataBound">
 3         <Columns>
 4         <asp:BoundField DataField="编号" HeaderText ="编号" />
 5         <asp:BoundField DataField ="姓名" HeaderText ="姓名" />
 6         <asp:BoundField DataField ="邮政编码" HeaderText ="邮政编码" />
 7         <asp:BoundField DataField ="家庭住址" HeaderText ="家庭住址" />
 8        <asp:TemplateField HeaderText ="出生年月">
 9        <ItemTemplate>
10        <%#Eval("出生年月","{0:yyyy-MM-dd}")%>
11        </ItemTemplate>
12        </asp:TemplateField>
13         <asp:BoundField DataField ="起薪" HeaderText ="起薪" />
14         </Columns>
15         </asp:GridView>

 1  protected void Page_Load(object sender, EventArgs e)
 2     {
 3         if (!IsPostBack)
 4         {
 5             databind();
 6         }
 7 
 8     }
 9     public void databind()
10     {
11         SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["Conn"].ToString());
12         SqlCommand cmd = new SqlCommand();
13         cmd.Connection = con;
14         cmd.CommandText = "select * from T_Message";
15         SqlDataAdapter da = new SqlDataAdapter(cmd);
16         DataSet ds = new DataSet();
17         da.Fill(ds);
18         this.GridView1.DataSource = ds.Tables[0];
19         this.GridView1.DataBind();
20     }
21     double sum = 0;
22     protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
23     {
24         foreach (TableCell item in e.Row.Cells)
25         {
26             item.Attributes.Add("style", "border-color:black");
27         }
28       
29         if (e.Row.RowType == DataControlRowType.DataRow)
30         {
31             sum = sum + Convert.ToInt32(e.Row.Cells[5].Text);
32         }
33         if (e.Row.RowType == DataControlRowType.Footer)
34         {
35             e.Row.Cells[4].Text = "每月支出薪水";
36             e.Row.Cells[2].Text = "平均薪水";
37             e.Row.Cells[3].Text = (sum / GridView1.Rows.Count).ToString();
38             e.Row.Cells[5].Text = sum.ToString();
39         }
40     }