.Net Core MVC 网站开发(Ninesky) 2.3、项目架构调整(续)-使用配置文件动态注入

2016-12-27 08:16:26来源:cnblogs.com作者:洞庭夕照人点击

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上次实现了依赖注入,但是web项目必须要引用业务逻辑层和数据存储层的实现,项目解耦并不完全;另一方面,要同时注入业务逻辑层和数据访问层,注入的服务直接写在Startup中显得非常臃肿。理想的方式是,web项目近引用接口而不引用实现,在配置文件中进行配置实现程序集合类,注入业务逻辑层而不必注入数据访问层。

一、数据访问层

在项目中摒弃数据访问层或者使用EntityFramework作为数据访问层。

在项目中数据访问层主要实现数据的存储,仔细看一下EntityFramework发现DbContext的功能完全实现了查、增、删、改等各种操作,并且有缓存等功能,本身就实现了仓储模式,并且比自己封装的数据存储层的功能还强大,干脆在项目中用EntityFramework作为数据存储层。删除掉Ninesky.InterfaceDataLibrary项目和Ninesky.DataLibrary项目。

注:项目结构调整的确实太频繁了,以后一段时间内绝不再调整了。

二、实现业务逻辑层。

添加业务逻辑层接口项目Ninesky.InterfaceBase

1、添加接口基类接口InterfaceBaseService,添加基本的查、增、删、改方法

using Ninesky.Models;using System;using System.Linq;using System.Linq.Expressions;namespace Ninesky.InterfaceBase{    /// <summary>    ///  服务基础接口    /// </summary>    public interface InterfaceBaseService<T> where T:class    {        /// <summary>        /// 添加        /// </summary>        /// <param name="entity">实体</param>        /// <param name="isSave">是否立即保存</param>        /// <returns>添加的记录数</returns>        int Add(T entity, bool isSave = true);        /// <summary>        /// 添加[批量]        /// </summary>        /// <param name="entities">实体</param>        /// <param name="isSave">是否立即保存</param>        /// <returns>添加的记录数</returns>        int AddRange(T[] entities, bool isSave = true);        /// <summary>        /// 查询记录数        /// </summary>        /// <param name="predicate">查询条件</param>        /// <returns>记录数</returns>        int Count(Expression<Func<T, bool>> predicate);        /// <summary>        /// 查询是否存在        /// </summary>        /// <param name="predicate">查询条件</param>        /// <returns>是否存在</returns>        bool Exists(Expression<Func<T, bool>> predicate);        /// <summary>        /// 查找        /// </summary>        /// <param name="Id">主键</param>        /// <returns></returns>        T Find(int Id);        /// <summary>        /// 查找        /// </summary>        /// <param name="keyValues">主键</param>        /// <returns></returns>        T Find(object[] keyValues);        /// <summary>        /// 查找        /// </summary>        /// <param name="predicate">查询条件</param>        /// <returns></returns>        T Find(Expression<Func<T, bool>> predicate);        IQueryable<T> FindList<TKey>(int number, Expression<Func<T, bool>> predicate);        /// <summary>        /// 查询        /// </summary>        /// <typeparam name="TKey">排序属性</typeparam>        /// <param name="number">显示数量[小于等于0-不启用]</param>        /// <param name="predicate">查询条件</param>        /// <param name="keySelector">排序</param>        /// <param name="isAsc">正序</param>        /// <returns></returns>        IQueryable<T> FindList<TKey>(int number, Expression<Func<T, bool>> predicate, Expression<Func<T, TKey>> keySelector, bool isAsc);        /// <summary>        /// 查询[分页]        /// </summary>        /// <typeparam name="TKey">排序属性</typeparam>        /// <param name="predicate">查询条件</param>        /// <param name="keySelector">排序</param>        /// <param name="isAsc">是否正序</param>        /// <param name="paging">分页数据</param>        /// <returns></returns>        Paging<T> FindList<TKey>(Expression<Func<T, bool>> predicate, Expression<Func<T, TKey>> keySelector, bool isAsc, Paging<T> paging);        /// <summary>        /// 查询[分页]        /// </summary>        /// <typeparam name="TKey">排序属性</typeparam>        /// <param name="predicate">查询条件</param>        /// <param name="keySelector">排序</param>        /// <param name="isAsc">是否正序</param>        /// <param name="pageIndex">当前页</param>        /// <param name="pageSize">每页记录数</param>        /// <returns></returns>        Paging<T> FindList<TKey>(Expression<Func<T, bool>> predicate, Expression<Func<T, TKey>> keySelector, bool isAsc, int pageIndex, int pageSize);        /// <summary>        /// 删除        /// </summary>        /// <param name="entity">实体</param>        /// <param name="isSave">是否立即保存</param>        /// <returns>是否删除成功</returns>        bool Remove(T entity, bool isSave = true);        /// <summary>        /// 删除[批量]        /// </summary>        /// <param name="entities">实体数组</param>        /// <param name="isSave">是否立即保存</param>        /// <returns>成功删除的记录数</returns>        int RemoveRange(T[] entities, bool isSave = true);        /// <summary>        ///  保存到数据库        /// </summary>        /// <returns>更改的记录数</returns>        int SaveChanges();        /// <summary>        /// 更新        /// </summary>        /// <param name="entity">实体</param>        /// <param name="isSave">是否立即保存</param>        /// <returns>是否保存成功</returns>        bool Update(T entity, bool isSave = true);        /// <summary>        /// 更新[批量]        /// </summary>        /// <param name="entities">实体数组</param>        /// <param name="isSave">是否立即保存</param>        /// <returns>更新成功的记录数</returns>        int UpdateRange(T[] entities, bool isSave = true);    }}

2、在Ninesky.Base中添加,接口InterfaceBaseService的实现类BaseService.cs

using Microsoft.EntityFrameworkCore;using Ninesky.InterfaceBase;using Ninesky.Models;using System;using System.Linq;using System.Linq.Expressions;namespace Ninesky.Base{    /// <summary>    /// 服务基类    /// </summary>    public class BaseService<T>:InterfaceBaseService<T> where T:class    {        protected DbContext _dbContext;        public BaseService(DbContext dbContext)        {            _dbContext = dbContext;        }        public virtual int Add(T entity, bool isSave = true)        {            _dbContext.Set<T>().Add(entity);            if (isSave) return _dbContext.SaveChanges();            else return 0;        }        public virtual int AddRange(T[] entities, bool isSave = true)        {            _dbContext.Set<T>().AddRange(entities);            if (isSave) return _dbContext.SaveChanges();            else return 0;        }        /// <summary>        /// 查询记录数        /// </summary>        /// <param name="predicate">查询条件</param>        /// <returns>记录数</returns>        public virtual int Count(Expression<Func<T, bool>> predicate)        {            return _dbContext.Set<T>().Count(predicate);        }        /// <summary>        /// 查询是否存在        /// </summary>        /// <param name="predicate">查询条件</param>        /// <returns>是否存在</returns>        public virtual bool Exists(Expression<Func<T, bool>> predicate)        {            return Count(predicate) > 0;        }        /// <summary>        /// 查找        /// </summary>        /// <param name="Id">主键</param>        /// <returns></returns>        public virtual T Find(int Id)        {            return _dbContext.Set<T>().Find(Id);        }        public virtual T Find(object[] keyValues)        {            return _dbContext.Set<T>().Find(keyValues);        }        public virtual T Find(Expression<Func<T, bool>> predicate)        {            return _dbContext.Set<T>().SingleOrDefault(predicate);        }        public virtual IQueryable<T> FindList<TKey>(int number, Expression<Func<T, bool>> predicate)        {            var entityList = _dbContext.Set<T>().Where(predicate);            if (number > 0) return entityList.Take(number);            else return entityList;        }        public virtual IQueryable<T> FindList<TKey>(int number, Expression<Func<T, bool>> predicate, Expression<Func<T, TKey>> keySelector, bool isAsc)        {            var entityList = _dbContext.Set<T>().Where(predicate);            if (isAsc) entityList = entityList.OrderBy(keySelector);            else entityList.OrderByDescending(keySelector);            if (number > 0) return entityList.Take(number);            else return entityList;        }        public virtual Paging<T> FindList<TKey>(Expression<Func<T, bool>> predicate, Expression<Func<T, TKey>> keySelector, bool isAsc, Paging<T> paging)        {            var entityList = _dbContext.Set<T>().Where(predicate);            paging.Total = entityList.Count();            if (isAsc) entityList = entityList.OrderBy(keySelector);            else entityList.OrderByDescending(keySelector);            paging.Entities = entityList.Skip((paging.PageIndex - 1) * paging.PageSize).Take(paging.PageSize).ToList();            return paging;        }        public virtual Paging<T> FindList<TKey>(Expression<Func<T, bool>> predicate, Expression<Func<T, TKey>> keySelector, bool isAsc, int pageIndex, int pageSize)        {            Paging<T> paging = new Paging<T> { PageIndex = pageIndex, PageSize = pageSize };            return FindList(predicate, keySelector, isAsc, paging);        }        /// <summary>        /// 删除        /// </summary>        /// <param name="entity">实体</param>        /// <param name="isSave">是否立即保存</param>        /// <returns>是否删除成功</returns>        public virtual bool Remove(T entity, bool isSave = true)        {            _dbContext.Set<T>().Remove(entity);            if (isSave) return _dbContext.SaveChanges() > 0;            else return false;        }        /// <summary>        /// 删除[批量]        /// </summary>        /// <param name="entities">实体数组</param>        /// <param name="isSave">是否立即保存</param>        /// <returns>成功删除的记录数</returns>        public virtual int RemoveRange(T[] entities, bool isSave = true)        {            _dbContext.Set<T>().RemoveRange(entities);            if (isSave) return _dbContext.SaveChanges();            else return 0;        }        public virtual int SaveChanges()        {            return _dbContext.SaveChanges();        }        /// <summary>        /// 更新        /// </summary>        /// <param name="entity">实体</param>        /// <param name="isSave">是否立即保存</param>        /// <returns>是否保存成功</returns>        public virtual bool Update(T entity, bool isSave = true)        {            _dbContext.Set<T>().Update(entity);            if (isSave) return _dbContext.SaveChanges() > 0;            else return false;        }        /// <summary>        /// 更新[批量]        /// </summary>        /// <param name="entities">实体数组</param>        /// <param name="isSave">是否立即保存</param>        /// <returns>更新成功的记录数</returns>        public virtual int UpdateRange(T[] entities, bool isSave = true)        {            _dbContext.Set<T>().UpdateRange(entities);            if (isSave) return _dbContext.SaveChanges();            else return 0;        }    }}

3、在Ninesky.InterfaceBase项目中添加栏目接口InterfaceCategoryService.cs,新增了一个Findtree的方法

using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;using Ninesky.Models;namespace Ninesky.InterfaceBase{    /// <summary>    /// 栏目服务接口    /// </summary>    public interface InterfaceCategoryService:InterfaceBaseService<Category>    {        /// <summary>        /// 查找树形菜单        /// </summary>        /// <param name="categoryType">栏目类型,可以为空</param>        /// <returns></returns>        List<Category> FindTree(CategoryType? categoryType);    }}

4、在Ninesky.Base中添加栏目接口的实现类CategoryService.cs

using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;using Microsoft.EntityFrameworkCore;using Ninesky.Models;using Ninesky.InterfaceBase;namespace Ninesky.Base{    /// <summary>    /// 栏目服务类    /// </summary>    public class CategoryService:BaseService<Category>,InterfaceCategoryService    {        public CategoryService(DbContext dbContext):base(dbContext)        {        }        /// <summary>        /// 查找        /// </summary>        /// <param name="Id">栏目ID</param>        /// <returns></returns>        public override Category Find(int Id)        {            return _dbContext.Set<Category>().Include("General").Include("Page").Include("Link").SingleOrDefault(c => c.CategoryId == Id);        }        /// <summary>        /// 查找树形菜单        /// </summary>        /// <param name="categoryType">栏目类型,可以为空</param>        /// <returns></returns>        public List<Category> FindTree(CategoryType? categoryType)        {            var categories = _dbContext.Set<Category>().AsQueryable();            //根据栏目类型分类处理            switch (categoryType)            {                case null:                    break;                case CategoryType.General:                    categories = categories.Where(c => c.Type == categoryType);                    break;                    //默认-Page或Link类型                default:                    //Id数组-含本栏目及父栏目                    List<int> idArray = new List<int>();                    //查找栏目id及父栏目路径                    var categoryArray = categories.Where(c => c.Type == categoryType).Select(c => new { CategoryId = c.CategoryId, ParentPath = c.ParentPath });                    if(categoryArray != null)                    {                        //添加栏目ID到                        idArray.AddRange(categoryArray.Select(c => c.CategoryId));                        foreach (var parentPath in categoryArray.Select(c=>c.ParentPath))                        {                            var parentIdArray = parentPath.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);                            if (parentIdArray != null)                            {                                int parseId = 0;                                foreach(var parentId in parentIdArray)                                {                                    if (int.TryParse(parentId, out parseId)) idArray.Add(parseId);                                }                            }                        }                    }                    categories = categories.Where(c => idArray.Contains(c.CategoryId));                    break;            }            return categories.OrderBy(c => c.ParentPath).ThenBy(C => C.Order).ToList();        }    }}

三、实现dll动态加载和注入

要在web项目中对实现类进行解耦和注入,那么项目只能对接口进行依赖,解除对实现的依赖,然后在配置文件中配置实现的程序集和注入的服务,在Startup类中读取配置文件并加载程序集,然后实现接口的注入。

1、解除实现类依赖

在Web项目中添加对Ninesky.InterfaceBase项目的引用,解除对Ninesky.Base项目的引用。

2、实现注入的配置文件

首先在Models项目中实现注入服务类型配置项ServiceItem

using Microsoft.Extensions.DependencyInjection;using Newtonsoft.Json;using Newtonsoft.Json.Converters;namespace Ninesky.Models{    /// <summary>    /// 注入服务配置    /// </summary>    public class ServiceItem    {        /// <summary>        /// 服务类型[含命名空间]        /// </summary>        public string ServiceType { get; set; }        /// <summary>        /// 实现类类型[含命名空间]        /// </summary>        public string ImplementationType { get; set; }        /// <summary>        /// 生命周期        /// </summary>        [JsonConverter(typeof(StringEnumConverter))]        public ServiceLifetime LifeTime { get; set; }    }}

然后在Models项目中实现注入需要加载的程序集配置项 AssemblyItem

using System.Collections.Generic;namespace Ninesky.Models{    /// <summary>    /// 程序集注入项目    /// </summary>    public class AssemblyItem    {        /// <summary>        ///  服务的程序集名称[不含后缀]        /// </summary>        public string ServiceAssembly { get; set; }        /// <summary>        /// 实现程序集名称[含后缀.dll]        /// </summary>        public string ImplementationAssembly { get; set; }        /// <summary>        /// 注入服务集合        /// </summary>        public List<ServiceItem> DICollections { get; set; }    }}

添加配置文件

在Web项目中添加配置文件service.json

{  "AssemblyCollections": [    {      "ServiceAssembly": "Ninesky.InterfaceBase",      "ImplementationAssembly": "Ninesky.Base.dll",      "DICollections": [        {          "ServiceType": "Ninesky.InterfaceBase.InterfaceCategoryService",          "ImplementationType": "Ninesky.Base.CategoryService",          "LifeTime": "Scoped"        }      ]    }  ]}

可以看到配置文件的键值对于AssemblyItem类和ServiceItem类对应。集合的服务程序集为Ninesky.InterfaceBase,实现程序集为Ninesky.Base.dll,注入的服务为Ninesky.InterfaceBase.InterfaceCategoryService,实现类是Ninesky.Base.CategoryService。

读取配置文件并绑定到类型

在Startup只需要一行到即可绑定配置到类型。读取配置文件并绑定的详细操作见《Asp.Net Core自定义配置并绑定》

var assemblyCollections =  new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddJsonFile("service.json").Build().GetSection("AssemblyCollections").Get<List<AssemblyItem>>();

3、进行注入

在assemblyCollections变量加载了配置文件后使用如下代码即可实现注入

            foreach(var assembly in assemblyCollections)            {                var serviceAssembly = Assembly.Load(new AssemblyName(assembly.ServiceAssembly));                var implementationAssembly = AssemblyLoadContext.Default.LoadFromAssemblyPath(AppContext.BaseDirectory + "//" + assembly.ImplementationAssembly);                foreach(var service in assembly.DICollections)                {                    services.Add(new ServiceDescriptor(serviceAssembly.GetType(service.ServiceType), implementationAssembly.GetType(service.ImplementationType), service.LifeTime));                }            }

代码中可以看到加载接口程序集使用的方法是Assembly.Load(new AssemblyName(assembly.ServiceAssembly)),这是因为项目引用了接口程序集的项目,加载程序集的时候只需要提供程序集的名称就可以。

加载实现类所在程序集的时候使用的是AssemblyLoadContext.Default.LoadFromAssemblyPath(AppContext.BaseDirectory + "//" + assembly.ImplementationAssembly)。在.Net Core中Assembly没有了LoadFrom方法,仅有一个Load方法加载已引用的程序集。多方搜索资料才找到AssemblyLoadContext中有一个方法可以不需要引用项目可以动态加载Dll,但必须包含Dll的完整路径。

 

 

到这里就完整实现了解耦,现在项目结构看起来是这样子

image

解耦后有些麻烦的是修改Base项目的代码后运行项目会出错,必须生成项目后将Base项目生成的Ninesky.Base.dll和Ninesky.Base.pdb复制到Web项目的bin/Debug/netcoreapp1.1目录下才能正常运行。

F5运行一下可以看到正常读出了数据。

image

 

四、其他

 

代码托管地址:https://git.oschina.net/ninesky/Ninesky

文章发布地址:http://www.ninesky.cn

                 http://mzwhj.cnblogs.com/

代码包下载:Ninesky2.3、项目架构调整(续)-使用配置文件动态注入.rar

 

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