asp.net中显示DataGrid控件列序号的几种方法

晨曦之光 发布于 2012/03/09 15:04
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aps.net中多数据绑定的控件很多,论功能来说,应该属DataGrid最为齐全,但它没有提供现成的显示记录序号的功能,不过我们可以通过它所带的一些参数来间接得到序号,下面来看看怎样得到和显示序号值计算方式如下:

(1)在后台

DataGrid.CurrentPageIndex * DataGrid.PageSize + e.Item.ItemIndex + 1

(2)在前台

DataGrid1.CurrentPageIndex * DataGrid1.PageSize + Container.ItemIndex + 1

说明:

e表示System.Web.UI.WebControls.DataGridItemEventArgs参数类的实例;

DataGrid1这里表示前台的一个实例;

DataGrid.CurrentPageIndex:获取或设置当前显示页的索引;

DataGrid.PageSize :获取或设置要在 DataGrid 控件的单页上显示的项数。

 

下面我使用了4种方法来在前台显示序号,不过都是围绕上面的计算式展开。

(1)         使用DataGridItemCreated设置值,而前台的单元格可以是绑定列或者模板列(包括空模板)

(2)         使用DataGridItemDataBound设置值,而前台的单元格可以是绑定列或者模板列(包括空模板)

(3)         在前台直接绑定计算表达式;

(4)         在后台类中编写方法计算表达式由前台页面类继承调用。

备注:在数据库中获取数据时设置额外的序号列这里不做讨论,我认为这是最糟糕的实现方法。

下面以获取Northwind数据库的Customers表的数据为列,显示如下:

序号1

序号2

序号3

序号4

序号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

 

下面是WebFormPaging.aspx文件代码,

<%@ Page language="c#" Codebehind="WebFormPaging.aspx.cs" AutoEventWireup="false" Inherits="AspnetPaging.WebForm1" %>

<!DOCTYPE HTML PUBLIC "-//W 3C //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="400" align="center" border="1">

                                     <TR>

                                               <TD><asp:datagrid id="DataGrid1" runat="server" AutoGenerateColumns="False" Width="100%" AllowPaging="True">

                                                                 <Columns>

                                                                           <asp:BoundColumn HeaderText="序号1"></asp:BoundColumn>

                                                                           <asp:TemplateColumn HeaderText="序号2"></asp:TemplateColumn>

                                                                           <asp:TemplateColumn HeaderText="序号3">

                                                                                    <ItemTemplate>

                                                                                             <asp:Label ID="itemIndex" runat="server"></asp:Label>

                                                                                    </ItemTemplate>

                                                                           </asp:TemplateColumn>

                                                                           <asp:TemplateColumn HeaderText="序号4">

                                                                                    <ItemTemplate>

                                                                                             <%# (DataGrid1.CurrentPageIndex * DataGrid1.PageSize + Container.ItemIndex + 1) %>

                                                                                    </ItemTemplate>

                                                                           </asp:TemplateColumn>

                                                                           <asp:TemplateColumn HeaderText="序号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>

 

后台WebFormPaging.aspx.cs代码如下:

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();

              }

         }

 

         //绑定数据

         private void DataGridDataBind()

         {

              DataSet ds = DataAccess.GetCustomersData();

              this.DataGrid1.DataSource = ds;

              this.DataGrid1.DataBind();

         }

 

        

 

         #region Web 窗体设计器生成的代码

         override protected void OnInit(EventArgs e)

         {

              InitializeComponent();

              base.OnInit(e);

         }

        

         /// <summary>

         /// 设计器支持所需的方法 - 不要使用代码编辑器修改

         /// 此方法的内容。

         /// </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

 

         //翻页

         private void DataGrid1_PageIndexChanged(object source, System.Web.UI.WebControls.DataGridPageChangedEventArgs e)

         {

              DataGrid1.CurrentPageIndex = e.NewPageIndex;

              DataGridDataBind();

         }

         //获取当前项

         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();

              }

         }

     }

}

 

数据层代码如下:

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;

         }

     }

}

 

总结,上面的四种方法前两种其实处理起来是一样的,只是处理的时间不同而已;对于第三种我认为最简单,直接在前台页面绑定,不需要额外的辅助;对于第四种的方法绑定到前台我认为最为灵活,需要注意的是GetRecordIndex方法需要protectedpublic,使它的继承类能访问的到。


原文链接:http://blog.csdn.net/21aspnet/article/details/226148
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