1.数据层的编写
NewListInfoDal.cs:
GetPageEntityList方法，根据start,end取出数据 --row_number() over()函数查询
LoadEntity方法：初始化，将datatable中的每行添加到对象中
GetRecordCount方法：获取T_news表中，总的条数
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;
using System.Data.SqlClient;
using Itcast.CMS.Model;
namespace Itcast.CMS.DAL
{
public class NewListInfoDal
{
/// <summary>
/// 用于分页，根据start,end 取出数据
/// </summary>
/// <param name="start"></param>
/// <param name="end"></param>
/// <returns></returns>
public List<T_News> GetPageEntityList(int start,int end)
{
string sql = " select * from (select row_number() over(order by id) as num, * from T_News) as t where t.num>[email protected] and t.num<[email protected] ";
SqlParameter[] pars ={
new SqlParameter("@start",SqlDbType.Int),
new SqlParameter("@end",SqlDbType.Int)
};
pars[0].Value = start;
pars[1].Value = end;
DataTable dt = DAL.SqlHelper.SelectSqlReturnDataTable(sql, CommandType.Text, pars);
List<T_News> newlist_list = null;
if(dt.Rows.Count>0)
{
newlist_list = new List<T_News>();
//遍历每一行添加到集合中
T_News newlist =null;
foreach(DataRow row in dt.Rows)
{
newlist = new T_News();
LoadEntity(row, newlist);
newlist_list.Add(newlist);
}
}
return newlist_list;
}
public void LoadEntity(DataRow row,T_News newlist)
{
newlist.Id = Convert.ToInt32(row["id"].ToString());
newlist.Title = row["Title"] != DBNull.Value ? row["Title"].ToString() : string.Empty;
newlist.Msg = row["Msg"] != DBNull.Value ? row["Msg"].ToString() : string.Empty;
newlist.Author = row["Author"] != DBNull.Value ? row["Author"].ToString() : string.Empty;
newlist.ImagePath = row["ImagePath"] != DBNull.Value ? row["ImagePath"].ToString() : string.Empty;
newlist.SubDateTime = Convert.ToDateTime(row["SubDateTime"].ToString());
}
/// <summary>
/// 获取T_News表中，总的条数
/// </summary>
/// <returns></returns>
public int GetRecordCount()
{
string sql = " select count(*) from T_News ";
object ob = DAL.SqlHelper.selectSqlReturnObject(sql, CommandType.Text);
ob = ob != DBNull.Value ? ob : string.Empty;
return Convert.ToInt32(ob.ToString());
}
}
}
2.业务层的编写
NewListInfoService.cs
GetPageEntityList方法：返回分页每页的数据 --公式计算出当前页和每页的条数
GetPageCount方法：获取总的页数 --总的条数/每页的条数
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Itcast.CMS.Model;
using Itcast.CMS.DAL;
namespace Itcast.CMS.BLL
{
public class NewListInfoService
{
DAL.NewListInfoDal NewListInfo = new DAL.NewListInfoDal();
/// <summary>
/// 返回每页的数据
/// </summary>
/// <param name="PageIndex">当前页</param>
/// <param name="PageSize">每页的条数</param>
/// <returns></returns>
public List<T_News> GetPageEntityList(int PageIndex,int PageSize)
{
//公式计算每页的第一条，最好一条
int start = (PageIndex - 1) * PageSize + 1;
int end = PageIndex * PageSize;
return NewListInfo.GetPageEntityList(start, end);
}
/// <summary>
/// 获取总的页数
/// </summary>
/// <returns></returns>
public int GetPageCount(int PageSize)
{
int recordCount = NewListInfo.GetRecordCount();
int PageCount = Convert.ToInt32(Math.Ceiling((double)recordCount / PageSize));
return PageCount;
}
}
}
3.控制器中的Index方法
{
获取当前页码值，
设置条数，
总的页码数，
PageIndex范围判断，
获取分页数据，
ViewData数据绑定
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using Itcast.CMS.Model;
namespace Itcast.CMS.WebApp.Controllers
{
public class NewListController : Controller
{
//
// GET: /NewList/
BLL.NewListInfoService NewListInfo = new BLL.NewListInfoService();
public ActionResult Index()
{
//获取当前页码值
int PageIndex = Request["PageIndex"] != null ? Convert.ToInt32(Request["PageIndex"]) : 1;
//设置条数
int PageSize = 5;
//总的页码数
int PageCount = NewListInfo.GetPageCount(PageSize);
//PageIndex范围判断
PageIndex = PageIndex < 1 ? 1 : PageIndex;
PageIndex = PageIndex > PageCount ? PageCount : PageIndex;
//获取分页数据
List<T_News> list = NewListInfo.GetPageEntityList(PageIndex, PageSize);
//ViewData...
ViewData["newInfoList"] = list;
ViewData["pageIndex"] = PageIndex;
ViewData["pageCount"] = PageCount;
return View();
}
}
}
4.生产分页的页码，Common中的PageBar类中的GetPageBar方法 --生产分页的字符
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Itcast.CMS.Common
{
public class PageBar
{
public static string GetPageBar(int pageIndex,int pageCount)
{
if (pageCount == 1)
{
return string.Empty;
}
int start = pageIndex - 5;
start = start < 1 ? 1 : start;
int end = start + 9;
if (end > pageCount)
{
end = pageCount;
start = end - 9 > 0 ? end - 9 : 1;
}
StringBuilder sb = new StringBuilder();
if (pageIndex > 1)
{
sb.Append(string.Format("<a href=‘?PageIndex={0}‘>上一页</a>", pageIndex - 1));
}
for (int i = start; i <= end; i++)
{
if (i == pageIndex)
{
sb.Append(i);
}
else
{
sb.Append(string.Format("<a href=‘?PageIndex={0}‘>{0}</a>", i));
}
}
if (pageIndex < pageCount)
{
sb.Append(string.Format("<a href=‘?PageIndex={0}‘>下一页</a>", pageIndex + 1));
}
return sb.ToString();
}
}
}
5.视图中的调用，Razor引擎视图的编写
@{
Layout = null;
}
@using Itcast.CMS.Model
@using Itcast.CMS.Common
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Index</title>
<link href="~/Content/tableStyle.css" rel="stylesheet" />
<link href="~/Content/pageBar.css" rel="stylesheet" />
</head>
<body>
<div>
@if(ViewData["newInfoList"]!=null)
{
<table width="100%">
<tr><th>编号</th><th>标题</th><th>作者</th><th>时间</th><th>详细</th><th>删除</th></tr>
@foreach(T_News newlist in (List<T_News>)ViewData["newInfoList"])
{
<tr>
<td>@newlist.Id</td>
<td>@newlist.Title</td>
<td>@newlist.Author</td>
<td>@newlist.SubDateTime</td>
<td>详细</td>
<td>删除</td>
</tr>
}
</table>
<div class="page_nav">@MvcHtmlString.Create(PageBar.GetPageBar((int)ViewData["pageIndex"], (int)ViewData["pageCount"]))</div>
}
else
{
<span>暂无数据</span>
}
</div>
</body>
</html>
时间： 2024-10-06 12:48:33