Asp.net|datagrid|datagrid Controls | Several ways to display the DataGrid control column ordinal in asp.net
Author: Zhengzo 2004-9-10
In the aps.net most of the binding control, the function of the DataGrid should be the most complete, but it does not provide a ready-made record number of functions, but we can use some of its parameters to get the serial number, the following see how to get and display ordinal value calculation method is as follows:
(1) in the background
Datagrid.currentpageindex * datagrid.pagesize + e.item.itemindex + 1
(2) at the front desk
Datagrid1.currentpageindex * datagrid1.pagesize + container.itemindex + 1
Description
E represents an instance of the System.Web.UI.WebControls.DataGridItemEventArgs parameter class;
DataGrid1 here represents an example of the foreground;
Datagrid.currentpageindex: Gets or sets the index of the currently displayed page;
Datagrid.pagesize: Gets or sets the number of items to display on a single page of the DataGrid control.
I've used 4 methods to display the serial number in the foreground, but it all revolves around the formula above.
(1) Use the itemcreated of the DataGrid to set the value, and the foreground cell can be a bound column or a template column (including an empty template);
(2) Use the ItemDataBound of the DataGrid to set the value, and the foreground cell can be a bound column or a template column (including an empty template);
(3) Directly binding the computation expression in the foreground;
(4) Writing a method evaluation expression in the background class inherits the call from the foreground page class.
Note: Set additional ordinal columns when fetching data in the database I think this is the worst way to do this without discussion.
The following is a column that gets the data for the Customers table of the Northwind database, as shown below:
Serial Number 1
Serial Number 2
Serial Number 3
Serial Number 4
Serial Number 5
CustomerID
51
51
51
51
51
Lonep
52
52
52
52
52
Magaa
53
53
53
53
53
Maisd
54
54
54
54
54
Merep
55
55
55
55
55
Morgk
56
56
56
56
56
Norts
57
57
57
57
57
OCEAN
58
58
58
58
58
Oldwo
59
59
59
59
59
Ottik
60
60
60
60
60
PARIS
1 2 3 4 5 6 7 8 9 10
Here is the webformpaging.aspx file code,
<%@ Page language= "C #" codebehind= "WebFormPaging.aspx.cs" autoeventwireup= "false" inherits= " Aspnetpaging.webform1 "%>
<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 transitional//en" >
<HTML>
<HEAD>
<title>WebForm1</title>
<meta content= "Microsoft Visual Studio. NET 7.1" name= "generator" >
<meta content= "C #" Name= "Code_language" >
<meta content= "JavaScript" name= "vs_defaultClientScript" >
<meta content= "http://schemas.microsoft.com/intellisense/ie5" name= "Vs_targetschema" >
</HEAD>
<body>
<form id= "Form1" method= "POST" runat= "Server" >
<table id= "Table1" cellspacing= "1" cellpadding= "1" width= "-" align= "center" border= "1" >
<TR>
<td><asp:datagrid id= "DATAGRID1" runat= "Server" autogeneratecolumns= "False" width= "100%" True ">
<Columns>
<asp:boundcolumn headertext= "serial number 1" ></asp:BoundColumn>
<asp:templatecolumn headertext= "Serial number 2" ></asp:TemplateColumn>
<asp:templatecolumn headertext= "serial number 3" >
<ItemTemplate>
<asp:label id= "ItemIndex" runat= "Server" ></asp:Label>
</ItemTemplate>
</asp:TemplateColumn>
<asp:templatecolumn headertext= "serial number 4" >
<ItemTemplate>
<%# (Datagrid1.currentpageindex * datagrid1.pagesize + container.itemindex + 1)%>
</ItemTemplate>
</asp:TemplateColumn>
<asp:templatecolumn headertext= "serial number 5" >
<ItemTemplate>
<%# Getrecordindex (Container.itemindex)%>
</ItemTemplate>
</asp:TemplateColumn>
<asp:boundcolumn datafield= "CustomerID" headertext= "CustomerID" ></asp:BoundColumn>
</Columns>
<pagerstyle mode= "NumericPages" ></PagerStyle>
</asp:datagrid></TD>
</TR>
<TR>
<TD></TD>
</TR>
<TR>
<TD></TD>
</TR>
</TABLE>
</form>
</body>
</HTML>
The background WebFormPaging.aspx.cs code is as follows:
Using System;
Using System.Collections;
Using System.ComponentModel;
Using System.Data;
Using System.Drawing;
Using System.Web;
Using System.Web.SessionState;
Using System.Web.UI;
Using System.Web.UI.WebControls;
Using System.Web.UI.HtmlControls;
Namespace Aspnetpaging
{
public class WebForm1:System.Web.UI.Page
{
private int recordCount = 0;
protected System.Web.UI.WebControls.DataGrid DataGrid1;
private void Page_Load (object sender, System.EventArgs e)
{
if (! Page.IsPostBack)
{
Datagriddatabind ();
}
}
Binding Data
private void Datagriddatabind ()
{
DataSet ds = Dataaccess.getcustomersdata ();
This. DataGrid1.DataSource = ds;
This. Datagrid1.databind ();
}
Code generated #region the Web forms Designer
Override protected void OnInit (EventArgs e)
{
InitializeComponent ();
Base. OnInit (e);
}
<summary>
Designer supports required methods-do not use the Code editor to modify
The contents of this method.
</summary>
private void InitializeComponent ()
{
This. datagrid1.itemcreated + = new System.Web.UI.WebControls.DataGridItemEventHandler (this. datagrid1_itemcreated);
This. Datagrid1.pageindexchanged + = new System.Web.UI.WebControls.DataGridPageChangedEventHandler (this. datagrid1_pageindexchanged);
This. Datagrid1.itemdatabound + = new System.Web.UI.WebControls.DataGridItemEventHandler (this. Datagrid1_itemdatabound);
This. Load + = new System.EventHandler (this. Page_Load);
}
#endregion
Page
private void Datagrid1_pageindexchanged (object source, System.Web.UI.WebControls.DataGridPageChangedEventArgs e)
{
Datagrid1.currentpageindex = E.newpageindex;
Datagriddatabind ();
}
Get current item
protected int Getrecordindex (int itemindex)
{
Return (Datagrid1.currentpageindex * datagrid1.pagesize + itemindex + 1);
}
private void Datagrid1_itemcreated (object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
{
DataGrid dg = (DataGrid) sender;
if (E.item.itemtype = = ListItemType.Item | | e.item.itemtype = = listitemtype.alternatingitem)
{
E.item.cells[0]. Text = (DG. CurrentPageIndex * DG. PageSize + E.item.itemindex + 1). ToString ();
E.ITEM.CELLS[1]. Text = (DG. CurrentPageIndex * DG. PageSize + E.item.itemindex + 1). ToString ();
}
}
private void Datagrid1_itemdatabound (object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
{
DataGrid dg = (DataGrid) sender;
if (E.item.itemtype = = ListItemType.Item | | e.item.itemtype = = listitemtype.alternatingitem)
{
((Label) E.item.findcontrol ("ItemIndex")). Text = (DG. CurrentPageIndex * DG. PageSize + E.item.itemindex + 1). ToString ();
}
}
}
}
The data layer code is as follows:
Using System;
Using System.Data;
Using System.Data.SqlClient;
Using System.Configuration;
Namespace Aspnetpaging
{
public class DataAccess
{
private static string connstring = configurationsettings.appsettings["ConnString"];
Private DataAccess ()
{
}
public static DataSet Getcustomersdata ()
{
SqlConnection conn = new SqlConnection (connstring);
SqlCommand comm = new SqlCommand ("GetCustomers", conn);
Comm.commandtype = CommandType.StoredProcedure;
SqlDataAdapter dataAdapter = new SqlDataAdapter (comm);
DataSet ds = new DataSet ();
DataAdapter.Fill (DS);
return DS;
}
}
}
Summing up, the above four methods in fact, the first two kinds of processing is the same, but the processing time is different; for the third I think the simplest, directly in the foreground page binding, does not require additional assistance; For the fourth method bound to the foreground I think the most flexible, It is to be noted that the Getrecordindex method requires protected or public so that its inheriting classes can be accessed.
