以Car表和Brand表为例，其中Car表的Brand是Brand表的Brandcode。
（1）建立两表的linq（一定要做好主外键关系，），创建之后不用修改，如要添加，另建文件。
（2）Car表的属性扩展（注意partial）
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web; /// <summary>
/// Car 的摘要说明
/// </summary>
public partial class Car
{ public string BrandStr
{ get {
return this.Brand1.Brand_Name; }
} }
（3）Car表和Brand表的封装方法（模糊查，开头，结尾，个数，最大值，最小值，平均值，求和，升序，降序，分页，组合查询都在CarData里面）
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web; /// <summary>
/// BrandData 的摘要说明
/// </summary>
public class BrandData
{
mydbDataContext cnn = null;
public BrandData()
{
cnn = new mydbDataContext();
} public List<Brand> quan()
{
return cnn.Brand.ToList(); } }
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web; /// <summary>
/// CarData 的摘要说明
/// </summary>
public class CarData
{
mydbDataContext cnn = null;
public CarData()
{
cnn = new mydbDataContext();
}
/// <summary>
/// 查询全部信息
/// </summary>
/// <returns>泛型集合</returns>
public List<Car> quan()
{
return cnn.Car.ToList();
}
/// <summary>
/// 根据名字模糊查询
/// </summary>
/// <param name="name">名称中的某一段字</param>
/// <returns>泛型集合</returns>
public List<Car> selectname(string name)
{
return cnn.Car.Where(r => r.Name.Contains(name)).ToList();
}
/// <summary>
/// 查询name以n开头的所有数据
/// </summary>
/// <param name="n">name以n开头的字</param>
/// <returns></returns>
public List<Car> selectstartname(string n)
{ return cnn.Car.Where(r => r.Name.StartsWith(n)).ToList();//r.name可以换成别的列
}
/// <summary>
/// 查询name以n结束的所有数据
/// </summary>
/// <param name="n">name以n结束的字</param>
/// <returns></returns>
public List<Car> selectendname(string n)
{ return cnn.Car.Where(r => r.Name.EndsWith(n)).ToList();//r.name可以换成别的列
}
/// <summary>
/// 查询价格最高的那个数
/// </summary>
/// <returns>最大数</returns>
public decimal? selectpricemax()
{
return cnn.Car.Max(r => r.Price);
}
/// <summary>
/// 查询价格最小的那个数
/// </summary>
/// <returns>最小数</returns>
public decimal? selectpricemin()
{
return cnn.Car.Min(r => r.Price);
}
/// <summary>
/// 查询价格的平均数
/// </summary>
/// <returns>平均数</returns>
public decimal? selectpriceavg()
{
return cnn.Car.Average(r=>r.Price);
}
/// <summary>
/// 查询价格的总数
/// </summary>
/// <returns>价格总数</returns>
public decimal? selectpricesum()
{
return cnn.Car.Sum(r=>r.Price);
}
/// <summary>
/// 按照价格升序进行排列的集合
/// </summary>
/// <returns>集合</returns>
public List<Car> order()
{
return cnn.Car.OrderBy(r=>r.Price).ToList();//按照价格升序
} /// <summary>
/// 按照价格降序进行排列的集合
/// </summary>
/// <returns>集合</returns>
public List<Car> descorder()
{
return cnn.Car.OrderByDescending(r => r.Price).ToList(); }
/// <summary>
/// 分页显示
/// </summary>
/// <param name="pagecount">每一页的页数</param>
/// <param name="num">第几页</param>
/// <returns>集合</returns>
public List<Car> fenye(int pagecount, int num)
{
return cnn.Car.Skip(pagecount * (num - )).Take(pagecount).ToList();//cnn.Car表示所有的数据
}
/// <summary>
/// 组合分页查询
/// </summary>
/// <param name="clist">所需要分页的集合</param>
/// <param name="pagecount">每一页的页数</param>
/// <param name="num">第几页</param>
/// <returns></returns>
public List<Car> zufen(List<Car> clist, int pagecount, int num)
{
return clist.Skip(pagecount * (num - )).Take(pagecount).ToList();//clist表示所需要分页的集合 }
}
（4）页面设计
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %> <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
</head>
<body>
<form id="form1" runat="server">
名称<asp:TextBox ID="name_text" runat="server"></asp:TextBox>
品牌<asp:DropDownList ID="brand_dd" runat="server"></asp:DropDownList>
价格<asp:DropDownList ID="pri_dd" runat="server">
<asp:ListItem>>=</asp:ListItem>
<asp:ListItem><=</asp:ListItem>
</asp:DropDownList><asp:TextBox ID="price_text" runat="server"></asp:TextBox>
<asp:Button ID="enter_btn" runat="server" Text="确定" />
<br />
<asp:Label ID="Label1" runat="server" Text=""></asp:Label>
<asp:Repeater ID="Repeater1" runat="server">
<HeaderTemplate>
<table style="width:100%; background-color:blue;">
<tr>
<td>序号</td>
<td>名称</td>
<td>品牌</td>
<td>时间</td>
<td>油耗</td>
<td>马力</td>
<td>价格</td>
<td>照片</td>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr style="background-color:gray" class="a">
<td><%#Container.ItemIndex+ %></td>
<td><%#Eval("Name") %></td>
<td><%#Eval("BrandStr") %></td>
<td><%#Eval("Time","{0:yyyy年MM月dd日}") %></td>
<td><%#Eval("Oil") %></td>
<td><%#Eval("Powers") %></td>
<td><%#Eval("Price") %></td>
<td><%#Eval("Pic") %></td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
当前第【<asp:Label ID="numLabel" runat="server" Text=""></asp:Label>】页，共【<asp:Label ID="sumLabel" runat="server" Text=""></asp:Label>】页
<asp:LinkButton ID="previewButton" runat="server">上一页</asp:LinkButton>
<asp:LinkButton ID="nextButton" runat="server">下一页</asp:LinkButton>
跳转到第<asp:DropDownList ID="page_dd" runat="server" AutoPostBack="true"></asp:DropDownList>页
</form>
</body>
</html>
<script>
var all = new Array();
all =document.getElementsByClassName("a"); for (var i = ; i < all.length; i++)
{
var old;
all[i].onmouseover = function ()
{
old = this.style.backgroundColor;
this.style.backgroundColor = "yellow";
}
all[i].onmouseout = function () { this.style.backgroundColor = old;
}
} </script>
（5）C#端代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls; public partial class _Default : System.Web.UI.Page
{
int pagecount = ;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
List<Car> list = new CarData().quan();
Repeater1.DataSource = new CarData().fenye(pagecount, ); ;
Repeater1.DataBind(); List<Brand> blist = new BrandData().quan();
brand_dd.Items.Add(new ListItem("全部","null"));
for(int i=;i<blist.Count;i++)
{
brand_dd.Items.Add(new ListItem(blist[i].Brand_Name,blist[i].Brand_Code));
} numLabel.Text = "";
sumLabel.Text = pagemax(list, pagecount).ToString();
for (int i = ; i <= int.Parse(sumLabel.Text); i++)
{
page_dd.Items.Add(new ListItem(i.ToString(),i.ToString()));
}
}
enter_btn.Click += enter_btn_Click;//查询按钮点击事件
nextButton.Click += nextButton_Click;//下一页的点击事件
previewButton.Click += previewButton_Click;//上一页的事件
page_dd.SelectedIndexChanged += page_dd_SelectedIndexChanged;//跳转到第几页事件
} void page_dd_SelectedIndexChanged(object sender, EventArgs e)//跳转到第几页事件
{
int c = int.Parse(page_dd.SelectedValue);
using (mydbDataContext cnn = new mydbDataContext())//运用多个集合的交集方法
{
int aa = int.Parse(page_dd.SelectedValue);
numLabel.Text = aa.ToString();//第几页中的页数
var all = cnn.Car.AsEnumerable();//相当于拼接sql语句
if (name_text.Text.Trim().Length > )
{
var nlist = cnn.Car.Where(r => r.Name.Contains(name_text.Text.Trim()));
all = all.Intersect(nlist);//取all集合和nlist集合的公共部分
}
if (brand_dd.SelectedValue == "null")
{ }
else
{ var blist = cnn.Car.Where(r => r.Brand == brand_dd.SelectedValue);
all = all.Intersect(blist);
}
if (price_text.Text.Trim().Length > )
{ if (pri_dd.SelectedIndex == )
{ var plist = cnn.Car.Where(r => r.Price >= decimal.Parse(price_text.Text.Trim()));
all = all.Intersect(plist);
}
else
{
var plist = cnn.Car.Where(r => r.Price <= decimal.Parse(price_text.Text.Trim()));
all = all.Intersect(plist);
}
}
Repeater1.DataSource = new CarData().zufen(all.ToList(), pagecount,aa);
Repeater1.DataBind(); } } void previewButton_Click(object sender, EventArgs e)//上一页的事件
{
using (mydbDataContext cnn = new mydbDataContext())//运用多个集合的交集方法
{
int a = int.Parse(numLabel.Text) -;//哪一页的页数
if (a <= )//判断有没有到最后一页
{
return;
}
numLabel.Text = a.ToString();//第几页中的页数
var all = cnn.Car.AsEnumerable();//相当于拼接sql语句
if (name_text.Text.Trim().Length > )
{
var nlist = cnn.Car.Where(r => r.Name.Contains(name_text.Text.Trim()));
all = all.Intersect(nlist);//取all集合和nlist集合的公共部分
}
if (brand_dd.SelectedValue == "null")
{ }
else
{ var blist = cnn.Car.Where(r => r.Brand == brand_dd.SelectedValue);
all = all.Intersect(blist);
}
if (price_text.Text.Trim().Length > )
{ if (pri_dd.SelectedIndex == )
{ var plist = cnn.Car.Where(r => r.Price >= decimal.Parse(price_text.Text.Trim()));
all = all.Intersect(plist);
}
else
{
var plist = cnn.Car.Where(r => r.Price <= decimal.Parse(price_text.Text.Trim()));
all = all.Intersect(plist);
}
}
Repeater1.DataSource = new CarData().zufen(all.ToList(), pagecount, a);
Repeater1.DataBind();
}
} void nextButton_Click(object sender, EventArgs e)//下一页的点击事件
{
using (mydbDataContext cnn = new mydbDataContext())//运用多个集合的交集方法
{
int a = int.Parse(numLabel.Text) + ;//哪一页的页数
if (a > int.Parse(sumLabel.Text))//判断有没有到最后一页
{
return;
}
numLabel.Text = a.ToString();//第几页中的页数
var all = cnn.Car.AsEnumerable();//相当于拼接sql语句
if (name_text.Text.Trim().Length > )
{
var nlist = cnn.Car.Where(r => r.Name.Contains(name_text.Text.Trim()));
all = all.Intersect(nlist);//取all集合和nlist集合的公共部分
}
if (brand_dd.SelectedValue == "null")
{ }
else
{ var blist = cnn.Car.Where(r => r.Brand == brand_dd.SelectedValue);
all = all.Intersect(blist);
}
if (price_text.Text.Trim().Length > )
{ if (pri_dd.SelectedIndex == )
{ var plist = cnn.Car.Where(r => r.Price >= decimal.Parse(price_text.Text.Trim()));
all = all.Intersect(plist);
}
else
{
var plist = cnn.Car.Where(r => r.Price <= decimal.Parse(price_text.Text.Trim()));
all = all.Intersect(plist);
}
}
Repeater1.DataSource = new CarData().zufen(all.ToList(),pagecount,a);
Repeater1.DataBind(); } } void enter_btn_Click(object sender, EventArgs e)//查询按钮点击事件
{
using (mydbDataContext cnn = new mydbDataContext())//运用多个集合的交集方法
{
page_dd.Items.Clear();
var all = cnn.Car.AsEnumerable();//相当于拼接sql语句
if (name_text.Text.Trim().Length>)
{
var nlist = cnn.Car.Where(r => r.Name.Contains(name_text.Text.Trim()));
all = all.Intersect(nlist);
}
if (brand_dd.SelectedValue == "null")
{ }
else
{ var blist = cnn.Car.Where(r => r.Brand == brand_dd.SelectedValue);
all = all.Intersect(blist);
}
if (price_text.Text.Trim().Length > )
{ if (pri_dd.SelectedIndex == )
{ var plist = cnn.Car.Where(r => r.Price >= decimal.Parse(price_text.Text.Trim()));
all = all.Intersect(plist);
}
else
{
var plist = cnn.Car.Where(r => r.Price <= decimal.Parse(price_text.Text.Trim()));
all = all.Intersect(plist);
}
} Repeater1.DataSource = new CarData().zufen(all.ToList(), pagecount, );
Repeater1.DataBind();
sumLabel.Text = pagemax(all.ToList(), pagecount).ToString();
numLabel.Text = "";
for (int i = ; i <= pagemax(all.ToList(), pagecount); i++)
{
page_dd.Items.Add(new ListItem(i.ToString(),i.ToString()));
}
} //if (name_text.Text.Trim() == "" && brand_dd.SelectedValue=="null" && price_text.Text.Trim() == "")//如果没有条件就查询全部
//{
// Repeater1.DataSource = new CarData().quan();
// Repeater1.DataBind();
// return;
//} //Repeater1.DataSource = new CarData().selectname(name_text.Text.Trim());//根据name中的XXX模糊查询
// Repeater1.DataSource = new CarData().selectstartname(name_text.Text.Trim());//name以XXX开头来查询
//Repeater1.DataSource = new CarData().selectendname(name_text.Text.Trim());//name以XXX结束来查询
//Label1.Text = new CarData().selectendname(name_text.Text.Trim()).Count.ToString();//获取符合条件的个数。其实就是根据模糊查询查出来的集合的子集个数。
//Repeater1.DataSource = new CarData().descorder();//按照价格降序进行排列
//Label1.Text = new CarData().selectpricemax().ToString();//查询价格最大的那个数
//Label1.Text = new CarData().selectpriceavg().ToString();//查询价格的平均数
//Label1.Text = new CarData().selectpricesum().ToString();//查询价格的总数
//Repeater1.DataBind(); }
public int pagemax(List<Car> clist,int pagecount)//求最大页数
{
int a = clist.Count;
return Convert.ToInt32(Math.Ceiling(a / (pagecount * 1.0))); } }
完！！