ASPNET后台管理系统(MVC4+EF+Postsharp)源码

#Entity Framework Extended Library A library the extends the functionality of Entity Framework. ##Download The Entity Framework Extended library is available on nuget.org via package name `EntityFramework.Extended`. To install EntityFramework.Extended, run the following command in the Package Manager Console PM> Install-Package EntityFramework.Extended More information about NuGet package avaliable at https://nuget.org/packages/EntityFramework.Extended ##Development Builds Development builds are available on the myget.org feed. A development build is promoted to the main NuGet feed when it's determined to be stable. In your Package Manager settings add the following package source for development builds: http://www.myget.org/F/loresoft/ ##Features - [Batch Update and Delete](https://github.com/loresoft/EntityFramework.Extended/wiki/Batch-Update-and-Delete) - [Future Queries](https://github.com/loresoft/EntityFramework.Extended/wiki/Future-Queries) - [Query Result Cache](https://github.com/loresoft/EntityFramework.Extended/wiki/Query-Result-Cache) - [Audit Log](https://github.com/loresoft/EntityFramework.Extended/wiki/Audit-Log) ### Batch Update and Delete A current limitations of the Entity Framework is that in order to update or delete an entity you have to first retrieve it into memory. Now in most scenarios this is just fine. There are however some senerios where performance would suffer. Also, for single deletes, the object must be retrieved before it can be deleted requiring two calls to the database. Batch update and delete eliminates the need to retrieve and load an entity before modifying it. **Deleting** //delete all users where FirstName matches context.Users.Delete(u => u.FirstName == "firstname"); **Update** //update all tasks with status of 1 to status of 2 context.Tasks.Update( t => t.StatusId == 1, t2 => new Task {StatusId = 2}); //example of using an IQueryable as the filter for the update var users = context.Users.Where(u => u.FirstName == "firstname"); context.Users.Update(users, u => new User {FirstName = "newfirstname"}); ### Future Queries Build up a list of queries for the data that you need and the first time any of the results are accessed, all the data will retrieved in one round trip to the database server. Reducing the number of trips to the database is a great. Using this feature is as simple as appending `.Future()` to the end of your queries. To use the Future Queries, make sure to import the `EntityFramework.Extensions` namespace. Future queries are created with the following extension methods... - Future() - FutureFirstOrDefault() - FutureCount() Sample // build up queries var q1 = db.Users .Where(t => t.EmailAddress == "one@test.com") .Future(); var q2 = db.Tasks .Where(t => t.Summary == "Test") .Future(); // this triggers the loading of all the future queries var users = q1.ToList(); In the example above, there are 2 queries built up, as soon as one of the queries is enumerated, it triggers the batch load of both queries. // base query var q = db.Tasks.Where(t => t.Priority == 2); // get total count var q1 = q.FutureCount(); // get page var q2 = q.Skip(pageIndex).Take(pageSize).Future(); // triggers execute as a batch int total = q1.Value; var tasks = q2.ToList(); In this example, we have a common senerio where you want to page a list of tasks. In order for the GUI to setup the paging control, you need a total count. With Future, we can batch together the queries to get all the data in one database call. Future queries work by creating the appropriate IFutureQuery object that keeps the IQuerable. The IFutureQuery object is then stored in IFutureContext.FutureQueries list. Then, when one of the IFutureQuery objects is enumerated, it calls back to IFutureContext.ExecuteFutureQueries() via the LoadAction delegate. ExecuteFutureQueries builds a batch query from all the stored IFutureQuery objects. Finally, all the IFutureQuery objects are updated with the results from the query. ### Query Result Cache To cache query results, use the `FromCache` extension method located in the `EntityFramework.Extensions` namespace. Below is a sample caching query results. Simply construct the LINQ query as you normally would, then append the `FromCache` extension. //query is cached using the default settings var tasks = db.Tasks .Where(t => t.CompleteDate == null) .FromCache(); //query result is now cached 300 seconds var tasks = db.Tasks .Where(t => t.AssignedId == myUserId && t.CompleteDate == null) .FromCache(CachePolicy.WithDurationExpiration(TimeSpan.FromSeconds(300))); The Query Result Cache also supports tagging the cache so you can expire common cache entries by calling `Expire` on a cache tag. // cache assigned tasks var tasks = db.Tasks .Where(t => t.AssignedId == myUserId && t.CompleteDate == null) .FromCache(tags: new[] { "Task", "Assigned-Task-" + myUserId }); // some update happened to Task, expire Task tag CacheManager.Current.Expire("Task"); The `CacheManager` has support for providers. The default provider uses `MemoryCache` to store the cache entries. To create a custom provider, implement `ICacheProvider`. The custom provider will then need to be registered in the `Locator` container. // Replace cache provider with Memcached provider Locator.Current.Register<ICacheProvider>(() => new MemcachedProvider()); ### Audit Log The Audit Log feature will capture the changes to entities anytime they are submitted to the database. The Audit Log captures only the entities that are changed and only the properties on those entities that were changed. The before and after values are recorded. `AuditLogger.LastAudit` is where this information is held and there is a `ToXml()` method that makes it easy to turn the AuditLog into xml for easy storage. The AuditLog can be customized via attributes on the entities or via a Fluent Configuration API. Fluent Configuration // config audit when your application is starting up... var auditConfiguration = AuditConfiguration.Default; auditConfiguration.IncludeRelationships = true; auditConfiguration.LoadRelationships = true; auditConfiguration.DefaultAuditable = true; // customize the audit for Task entity auditConfiguration.IsAuditable<Task>() .NotAudited(t => t.TaskExtended) .FormatWith(t => t.Status, v => FormatStatus(v)); // set the display member when status is a foreign key auditConfiguration.IsAuditable<Status>() .DisplayMember(t => t.Name); Create an Audit Log var db = new TrackerContext(); var audit = db.BeginAudit(); // make some updates ... db.SaveChanges(); var log = audit.LastLog; ## License Copyright (c) 2012, LoreSoft All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: - Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. - Neither the name of LoreSoft nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIE