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为datagrid的自带分页添加首页、尾页及状态功能

作者:佚名      ASP.NET网站开发编辑:admin      更新时间:2022-07-23

DataGrid提供了分页功能,不过看上去功能有限,但是我们可以通过DataGrid的一些属性来获取状态以及增加首页、尾页功能按钮。这里没有使用DataGrid的自定义分页功能,如果在速度效率不是很讲究的情况下,由DataGrid自己管理分页还是不错的,付出的代价就是要把整个相关数据取出来后再删选指定页的数据。好处就是开发速度快,不需要写分页的存储过程。本文事例使用的是Sql Server中的Northwind数据库。运行界面如下:

对于前台的显示界面,我放了一个DataGrid;四个LinkButton导向按钮;四个Literal来显示纪录状态。
剩下的就是用表格定位。
这里需要设置DataGrid的AllowPaging属性为True,同时设置AllowCustomPaging属性位false(默认为false),设置PagerStyle的Visible属性为False,使前台不显示。
前台的代码如下:
<%@ Page language="c#" Codebehind="DataGridPaging.aspx.cs" AutoEventWireup="false" Inherits="ZZ.AspnetPaging.DataGridPaging" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
     <HEAD>
         <title>DataGridPaging</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" style="FONT-SIZE: 9pt" cellSpacing="1" cellPadding="1" width="450" align="center"
                   border="1">
                   <TR>
                       <TD><asp:datagrid id="DataGrid1" runat="server" PageSize="5" Width="100%" AllowPaging="True">
                                 <HeaderStyle Font-Size="9pt"></HeaderStyle>
                                 <FooterStyle Font-Size="9pt"></FooterStyle>
                                 <PagerStyle Visible="False" Font-Size="9pt" Mode="NumericPages"></PagerStyle>
                            </asp:datagrid></TD>
                   </TR>
              </TABLE>
              <TABLE id="Table2" style="FONT-SIZE: 9pt" cellSpacing="1" cellPadding="1" width="450" align="center"
                   border="1">
                   <TR>
                       <TD style="WIDTH: 207px">
                            <asp:linkbutton id="LBtnFirst" runat="server" CommandName="First">首页</asp:linkbutton>
                            <asp:linkbutton id="LBtnPRev" runat="server" CommandName="Prev">上一页</asp:linkbutton>
                            <asp:linkbutton id="LBtnNext" runat="server" CommandName="Next">下一页</asp:linkbutton>
                            <asp:linkbutton id="LBtnLast" runat="server" CommandName="Last">尾页</asp:linkbutton> </TD>
                       <TD>第
                            <asp:literal id="LtlPageIndex" runat="server"></asp:literal>页 共
                            <asp:literal id="LtlPageCount" runat="server"></asp:literal>页 每页
                            <asp:literal id="LtlPageSize" runat="server"></asp:literal>条 共
                            <asp:literal id="LtlRecordCount" runat="server"></asp:literal>条
                       </TD>
                   </TR>
              </TABLE>
         </form>
     </body>
</HTML>
后台cs文件代码,DataGridPaging类从System.Web.UI.Page继承,在数据绑定时需要注意没有数据的情况(0页时),以及当页数减少时避免前台正在反页导致缺页。
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;
using System.Data.SqlClient;
using System.Configuration;
 
namespace ZZ.AspnetPaging
{
     public class DataGridPaging : System.Web.UI.Page
     {
         private static string connString = ConfigurationSettings.AppSettings["ConnString"];
         private int recordCount;
         private int pageCount;
 
         protected System.Web.UI.WebControls.LinkButton LBtnFirst;
         protected System.Web.UI.WebControls.LinkButton LBtnPrev;
         protected System.Web.UI.WebControls.LinkButton LBtnNext;
         protected System.Web.UI.WebControls.LinkButton LBtnLast;
          protected System.Web.UI.WebControls.Literal LtlPageIndex;
         protected System.Web.UI.WebControls.Literal LtlPageCount;
         protected System.Web.UI.WebControls.Literal LtlPageSize;
         protected System.Web.UI.WebControls.Literal LtlRecordCount;
         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 = GetCustomersData();
              recordCount = ds.Tables[0].Rows.Count;
              //获取当前的页数
              pageCount = (int)Math.Ceiling( recordCount * 1.0 / PageSize);
              //避免纪录从有到无时,并且已经进行过反页的情况下CurrentPageIndex > PageCount出错
              if(recordCount ==0)
              {
                   this.DataGrid1.CurrentPageIndex = 0;
              }
              else if(this.DataGrid1.CurrentPageIndex >= pageCount)
              {
                   this.DataGrid1.CurrentPageIndex = pageCount - 1;
              }
              this.DataGrid1.DataSource = ds;
              this.DataGrid1.DataBind();
              NavigationStateChange();
         }
 
         #region Web 窗体设计器生成的代码
         override protected void OnInit(EventArgs e)
         {
              //
              // CODEGEN: 该调用是 asp.net Web 窗体设计器所必需的。
              //
              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.LBtnFirst.Click += new System.EventHandler(this.LBtnNavigation_Click);
              this.LBtnPrev.Click += new System.EventHandler(this.LBtnNavigation_Click);
              this.LBtnNext.Click += new System.EventHandler(this.LBtnNavigation_Click);
              this.LBtnLast.Click += new System.EventHandler(this.LBtnNavigation_Click);
              this.Load += new System.EventHandler(this.Page_Load);
 
         }
         #endregion
 
         private void LBtnNavigation_Click(object sender, System.EventArgs e)
         {
              LinkButton btn = (LinkButton)sender;
              switch(btn.CommandName)
              {
                   case "First":
                       PageIndex = 0;
                       break;
                   case "Prev"://if( PageIndex > 0 )
                            PageIndex = PageIndex - 1;
                       break;
                   case "Next"://if( PageIndex < PageCount -1)
                            PageIndex = PageIndex + 1;
                       break;
                   case "Last":
                       PageIndex = PageCount - 1;
                       break;
              }
              DataGridDataBind();             
         }
         //数据绑定
         public static DataSet GetCustomersData()
         {
              SqlConnection conn = new SqlConnection(connString);
              string sqlStr = "SELECT CustomerID, CompanyName,Address,Phone FROM Customers";
              SqlCommand comm = new SqlCommand( sqlStr ,conn);
              SqlDataAdapter dataAdapter = new SqlDataAdapter(comm);
              DataSet ds = new DataSet();
              dataAdapter.Fill(ds);
              return ds;
         }
 
         ///<summary>
         ///控制导航按钮或数字的状态
         ///</summary>
         public void NavigationStateChange()
         {
              if( PageCount <= 1 )//( RecordCount <= PageSize )//小于等于一页
              {
                   this.LBtnFirst.Enabled = false;
                   this.LBtnPrev.Enabled = false;
                   this.LBtnNext.Enabled = false;
                   this.LBtnLast.Enabled = false;
              }
              else //有多页
              {
                   if( PageIndex == 0 )//当前为第一页
                   {
                       this.LBtnFirst.Enabled = false;
                       this.LBtnPrev.Enabled = false;
                       this.LBtnNext.Enabled = true;
                       this.LBtnLast.Enabled = true;
                                    
                   }
                   else if( PageIndex == PageCount - 1 )//当前为最后页
                   {
                       this.LBtnFirst.Enabled = true;
                       this.LBtnPrev.Enabled = true;
                       this.LBtnNext.Enabled = false;
                       this.LBtnLast.Enabled = false;
                                    
                   }
                   else //中间页
                   {
                       this.LBtnFirst.Enabled = true;
                       this.LBtnPrev.Enabled = true;
                       this.LBtnNext.Enabled = true;
                       this.LBtnLast.Enabled = true;
                   }
                  
              }
              if(RecordCount == 0)//当没有纪录时DataGrid.PageCount会显示1页
                   this.LtlPageCount.Text = "0";
              else
                   this.LtlPageCount.Text = PageCount.ToString();
              if(RecordCount == 0)
                   this.LtlPageIndex.Text = "0";
              else
                   this.LtlPageIndex.Text = (PageIndex + 1).ToString();//在有页数的情况下前台显示页数加1
              this.LtlPageSize.Text = PageSize.ToString();
              this.LtlRecordCount.Text = RecordCount.ToString();
         }
 
        
         // 总页数
         public int PageCount
         {
              get{return this.DataGrid1.PageCount;}
         }
         //页大小
         public int PageSize
         {
              get{return this.DataGrid1.PageSize;}
         }
         //页索引,从零开始
         public int PageIndex
         {
              get{return this.DataGrid1.CurrentPageIndex;}
              set{this.DataGrid1.CurrentPageIndex = value;}
         }
         // 纪录总数
         public int RecordCount
         {
              get{return recordCount;}
              set{recordCount = value;}
         }
     }
}