一、实现的思路和结构图
Repository的共同性c<TEntity, bool>> expression); }BaseRepository代码 public class BaseRepository<TEntity> : IRepository<TEntity> where TEntity : class { protected readonly DbContext Context; public BaseRepository(DbContext context) { Context = context; } /// <summary> /// Gets all objects from database /// </summary> /// <returns></returns> public IQueryable<TEntity> All() { return Context.Set<TEntity>().AsQueryable(); } /// <summary> /// Gets objects from database by filter. /// </summary> /// <param name="predicate">Specified a filter</param> /// <returns></returns> public virtual IQueryable<TEntity> Filter(Expression<Func<TEntity, bool>> predicate) { return Context.Set<TEntity>().Where<TEntity>(predicate).AsQueryable<TEntity>(); } /// <summary> /// Gets objects from database with filtering and paging. /// </summary> /// <param name="filter">Specified a filter</param> /// <param name="total">Returns the total records count of the filter.</param> /// <param name="index">Specified the page index.</param> /// <param name="size">Specified the page size</param> /// <returns></returns> public virtual IQueryable<TEntity> Filter(Expression<Func<TEntity, bool>> filter, out int total, int index = 0, int size = 50) { var skipCount = index * size; var resetSet = filter != null ? Context.Set<TEntity>().Where<TEntity>(filter).AsQueryable() : Context.Set<TEntity>().AsQueryable(); resetSet = skipCount == 0 ? resetSet.Take(size) : resetSet.Skip(skipCount).Take(size); total = resetSet.Count(); return resetSet.AsQueryable(); } /// <summary> /// Gets the object(s) is exists in database by specified filter. /// </summary> /// <param name="predicate">Specified the filter expression</param> /// <returns></returns> public bool Contains(Expression<Func<TEntity, bool>> predicate) { return Context.Set<TEntity>().Any(predicate); } /// <summary> /// Find object by keys. /// </summary> /// <param name="keys">Specified the search keys.</param> /// <returns></returns> public virtual TEntity Find(params object[] keys) { return Context.Set<TEntity>().Find(keys); } /// <summary> /// Find object by specified expression. /// </summary> /// <param name="predicate"></param> /// <returns></returns> public virtual TEntity Find(Expression<Func<TEntity, bool>> predicate) { return Context.Set<TEntity>().FirstOrDefault<TEntity>(predicate); } /// <summary> /// Create a new object to database. /// </summary> /// <param name="t">Specified a new object to create.</param> /// <returns></returns> public virtual void Create(TEntity t) { Context.Set<TEntity>().Add(t); } /// <summary> /// Delete the object from database. /// </summary> /// <param name="t">Specified a existing object to delete.</param> public virtual void Delete(TEntity t) { Context.Set<TEntity>().Remove(t); } /// <summary> /// Delete objects from database by specified filter expression. /// </summary> /// <param name="predicate"></param> /// <returns></returns> public virtual int Delete(Expression<Func<TEntity, bool>> predicate) { var objects = Filter(predicate); foreach (var obj in objects) Context.Set<TEntity>().Remove(obj); return Context.SaveChanges(); } /// <summary> /// Update object changes and save to database. /// </summary> /// <param name="t">Specified the object to save.</param> /// <returns></returns> public virtual void Update(TEntity t) { try { var entry = Context.Entry(t); Context.Set<TEntity>().Attach(t); entry.State = EntityState.Modified; } catch (OptimisticConcurrencyException ex) { throw ex; } } /// <summary> /// Select Single Item by specified expression. /// </summary> /// <param name="expression"></param> /// <returns></returns> public TEntity FirstOrDefault(Expression<Func<TEntity, bool>> expression) { return All().FirstOrDefault(expression); } }IUnitOfWork接口代码:IUnitOfWork接口定义了方法获取特定的Repository, 执行存储过程, SaveChange方法提交修改，统一更新数据。
public interface IUnitOfWork : IDisposable { DbContext DbContext { get; } TRepository GetRepository<TRepository>() where TRepository : class; void ExecuteProcedure(string procedureCommand, params object[] sqlParams); void ExecuteSql(string sql); List<T> SqlQuery<T>(string sql); void SaveChanges(); }UnitOfWork代码, 代码中使用到了Autofac中的IComponentContext来获取Repository实例
public class UnitOfWork : IUnitOfWork { private readonly IComponentContext _componentContext; protected readonly DbContext Context; public UnitOfWork(DbContext context, IComponentContext componentContext) { Context = context; _componentContext = componentContext; } public DbContext DbContext => Context; public TRepository GetRepository<TRepository>() where TRepository : class { return _componentContext.Resolve<TRepository>(); } public void ExecuteProcedure(string procedureCommand, params object[] sqlParams) { Context.Database.ExecuteSqlCommand(procedureCommand, sqlParams); } public void ExecuteSql(string sql) { Context.Database.ExecuteSqlCommand(sql); } public List<T> SqlQuery<T>(string sql) { return Context.Database.SqlQuery<T>(sql).ToList(); } public void SaveChanges() { try { Context.SaveChanges(); } catch (InvalidOperationException ex) { if (!ex.Message.Contains("The changes to the database were committed successfully")) { throw; } } } public void Dispose() { Context?.Dispose(); } }三、Repository设计的具体的使用
这里我们定义一个
IStudentRepository接口, 包含了方法GetAllStudents(), 同时继承于IRepository<Student>接口
public interface IStudentRepository : IRepository<Student>{ IEnumerable<dynamic> GetAllStudents();}接着定义StudentRepository类来实现这个接口
public class StudentRepository : BaseRepository<Student>, IStudentRepository{ private readonly SchoolContext _context; public StudentRepository(SchoolContext context) : base(context) { _context = context; } public IEnumerable<dynamic> GetAllStudents() { return _context.Students; }}在Application_Start方法中使用Autofac注册Repository的代码如下：var builder = new ContainerBuilder(); //register controllers builder.RegisterControllers(typeof(MvcApplication).Assembly); //register repository builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly()).AsImplementedInterfaces(); //add the Entity Framework context to make sure only one context per request builder.RegisterType<SchoolContext>().InstancePerRequest(); builder.Register(c => c.Resolve<SchoolContext>()).As<DbContext>().InstancePerRequest(); var container = builder.Build(); DependencyResolver.SetResolver(new AutofacDependencyResolver(container));在控制器中注入使用Repository的
private readonly IUnitOfWork _repositoryCenter;private readonly IStudentRepository _studentRepository;public HomeController(IUnitOfWork repositoryCenter){ _repositoryCenter = repositoryCenter; _studentRepository = _repositoryCenter.GetRepository<IStudentRepository>();}public ActionResult Index(Student sessionStudent){ var students = _studentRepository.GetAllStudents(); // 同时你也可以使用定义于IRepository<Student>中的方法， 比如: _studentRepository.Delete(students.First()); _repositoryCenter.SaveChanges(); ... return View(students);}四、思路总结
上面的设计，把Repository的通用代码剥离到父类中，同时又允许每个Repository扩展自己的方法，达到了比较理想的状态。
只是现在的设计和Autofac耦合了，但是如果想继续剥离Autofac直接使用 _repositoryCenter.GetRepository<IStudentRepository>(); 的方式获取IStudentRepository的实例就很困难了。
五、案例源码
源代码仓库 AutoFacMvc
到此这篇关于ASP.Net Core基于EF6、Unitwork、Autofac实现Repository模式的文章就介绍到这了。希望对大家的学习有所帮助，也希望大家多多支持我们。
