标签：des c style class blog code
在"MVC缓存01,运用控制器缓存或数据层缓存"中，在数据层中可以设置缓存的有用时刻。但这个还不够"智能"，常常期望在修改或创立的时分使缓存失效，加载新的数据。
?
□ 思路
1、缓存是以键值<string,
object="">寄存的，在创立缓存的时分，先把IDictionary<int,t>作为缓存内容存储,int为T的主键。
2、EF上下文保留的时分时分把改变保留到数据库，并更新缓存中的内容。
● 先找出上下文中状况为added或modified的实体：var changeobjects
●
把改变保留数据到数据库：context.SaveChanges()
●
依据缓存key获取类型为IDictionary<int,t>的缓存内容：var cacheData = Cache.Get("vehicles")
as Dictionary<int, vehicle="">;
●
最终遍历这些改变的实体，更新缓存项：cacheData[vehicle.Id] = vehicle;
□ 缓存接口
public interface ICacheProvider
{object Get(string key);
void Set(string key, object data, int cacheTime);
bool IsSet(string key);
void Invalidate(string key);
}
□ 缓存接口完成
环绕using System.Runtime.Caching的MemoryCache.Default回来类型为ObjectCache的缓存特点完成缓存接口：获取缓存项、设置缓存、判别是不是设置缓存、清空缓存。
using System;using System.Runtime.Caching;namespace MvcApplication1.Cache{public class DefaultCacheProvider : ICacheProvider
{ private ObjectCache Cache { get { return MemoryCache.Default; }}
public object Get(string key)
{ return Cache[key];}
public void Set(string key, object data, int cacheTime)
{ CacheItemPolicy policy = new CacheItemPolicy();policy.AbsoluteExpiration = DateTime.Now + TimeSpan.FromMinutes(cacheTime);
Cache.Add(new CacheItem(key, data), policy);}
public bool IsSet(string key)
{return (Cache[key] != null);
}
public void Invalidate(string key)
{Cache.Remove(key);
}
}
}
□ Model
public partial class Vehicle
{public int Id { get; set; }
public string Name { get; set; }
public decimal Price { get; set; }
}
□ 对于Vehicle的Repositoy接口：
using System.Collections.Generic;using MvcApplication1.Models;namespace MvcApplication1.Repository{public interface IVehicleRepository
{ void ClearCache();IEnumerableGetVehicles();
void Insert(Vehicle vehicle); void Update(Vehicle vehicle); void SaveChanges();}
}
□ 对于Vehicle的Repositoy接口完成：
using System.Collections.Generic;using System.Data;using System.Data.Entity.Infrastructure;using System.Linq;using MvcApplication1.Cache;using MvcApplication1.Models;namespace MvcApplication1.Repository{public class VehicleRepository : IVehicleRepository
{protected DemoEntities DataContext { get; private set; }
public ICacheProvider Cache { get; set; }public VehicleRepository() : this(new DefaultCacheProvider())
{}
public VehicleRepository(ICacheProvider cacheProvider) {this.DataContext = new DemoEntities();
this.Cache = cacheProvider;}
public void ClearCache()
{ Cache.Invalidate("vehicles");}
public System.Collections.Generic.IEnumerable GetVehicles() {var vehicles = Cache.Get("vehicles") as IDictionary<int, Vehicle>;
if (vehicles == null)
{vehicles = DataContext.Vehicle.ToDictionary(v => v.Id);
if (vehicles.Any()) { Cache.Set("vehicles",vehicles,30);}
}
return vehicles.Values;}
public void Update(Vehicle vehicle)
{if (vehicle != null)
{DataContext.Set().Attach(vehicle);
DataContext.Entry(vehicle).State = EntityState.Modified;
}
}
public void Insert(Vehicle vehicle)
{DataContext.Set().Add(vehicle);
}
public void SaveChanges()
{ //获取上下文中EntityState状况为added或modified的Vehiclevar changeobjects = DataContext.ChangeTracker.Entries();
//把改变保留到数据库DataContext.SaveChanges();
//更新缓存中有关的Vehiclevar cacheData = Cache.Get("vehicles") as Dictionary<int, Vehicle>;
if (cacheData != null)
{foreach (var item in changeobjects)
{ var vehicle = item.Entity as Vehicle;cacheData[vehicle.Id] = vehicle;
}
}
}
}
}
在保留缓存Cache.Set("vehicles",vehicles,30)之前，把从上下文获取到的数据转换成IDictionary<int,t>类型vehicles = DataContext.Vehicle.ToDictionary(v => v.Id);
□ HomeController
using System.Linq;using System.Web;using System.Web.Mvc;using MvcApplication1.Models;using MvcApplication1.Repository;namespace MvcApplication1.Controllers{public class HomeController : Controller
{ public IVehicleRepository Repository { get; set; } public HomeController(IVehicleRepository repository) { this.Repository = repository;}
public HomeController() : this(new VehicleRepository())
{}
public ActionResult Index() { return View(Repository.GetVehicles());}
[HttpPost]
public ActionResult Index(FormCollection form) {Repository.ClearCache();
return RedirectToAction("Index");
}
public ActionResult Edit(int id)
{var vehicle = Repository.GetVehicles().Single(v => v.Id == id);
return View(vehicle);}
[HttpPost]
public ActionResult Edit(Vehicle vehicle) {Repository.Update(vehicle);
Repository.SaveChanges();
return RedirectToAction("Index");
}
public ActionResult Create() {return View(new Vehicle());
}
[HttpPost]
public ActionResult Create(Vehicle vehicle) {Repository.Insert(vehicle);
Repository.SaveChanges();
return RedirectToAction("Index");
}
}
}
□ Home/Index.cshtml
@model IEnumerable
@{ ViewBag.Title = "Index"; Layout = "~/Views/Shared/_Layout.cshtml";}
"0" cellspacing="0" border="0">
@foreach (var vehicle in Model)
{}
| 编号 | 车型 | 报价 | |
|---|---|---|---|
| @vehicle.Id.ToString() | @vehicle.Name | @string.Format("{0:c}",vehicle.Price) | @Html.ActionLink("修改", "Edit", new { id=vehicle.Id }) |
@using (Html.BeginForm()){"submit" value="使缓存失效从头获取数据库数据" id="InvalidButton" name="InvalidButton"/>
}
@Html.ActionLink("创立", "Create")
□ Home/Create.cshtml
@model
MvcApplication1.Models.Vehicle @{ ViewBag.Title = "Create"; Layout
= "~/Views/Shared/_Layout.cshtml"; }
value="Create" />
} @section Scripts { @Scripts.Render("~/bundles/jqueryval") }
□ Home/Edit.cshtml
@model
MvcApplication1.Models.Vehicle @{ ViewBag.Title = "Edit"; Layout =
"~/Views/Shared/_Layout.cshtml"; }
value="Save" />
} @section Scripts { @Scripts.Render("~/bundles/jqueryval") }
□ 成果：
创立或修改之前： 
修改更新： 
创立： 
修改创立成功后： 
MVC缓存,使用数据层缓存,添加或修改时让缓存失效,布布扣,bubuko.com
标签：des c style class blog code
原文地址：http://www.cnblogs.com/miaoqing/p/3758512.html
