Based on ASP. 2.0 WebAPI Background Framework (1)-Dependency injection three-layer frame construction

Overview

This article describes how to build an ASP. 2.0 WebAPI Dependency Injection Three-tier architecture, why join dependencies, not to provide program performance, but to decouple between projects, to be more independent between projects.

• Microsoft Dad Official Documentation: in ASP. NET Core Dependency Injection

• Full understanding of ASP. NET Core Dependency Injection

Steps

1. Create a new solution and add an ASP. WEBAPI application

2. Add four. Net Core class Libraries: Entity, BLL, DAL, Common

3. Follow the solution layout below

4. Add a DAL layer file

• Under the DAL---Interfaces folder, add the interface IDalService.cs. Here the database context Dependency injection is prepared for the directory, which is added first.

     Public InterfaceIdalservice<t>whereT:class,New()    {        /// <summary>        ///New Entity/// </summary>        /// <param name= "entity" >Entity</param>        /// <returns></returns>T addentity (t entity); /// <summary>        ///Get Collection/// </summary>        /// <param name= "where" >LINQ Statements</param>        /// <returns></returns>Iqueryable<t> getentities (Expression<func<t,BOOL>>where); /// <summary>        ///Save Data/// </summary>        /// <returns></returns>        intSaveChanges (); }

Idalservice

• Under the Dal---Implements folder, add the base class DalService.cs.

 Public classDalservice<t>: IDisposable, idalservice<t>whereT:class,New()    {        Private ReadOnlyMycontext _context; /// <summary>        ///get the database context/// </summary>        /// <param name= "context" >database context for Dependency injection</param>         PublicDalservice (Mycontext context) {_context=context; }         PublicT addentity (t entity) {_context. Set<T>().            ADD (entity); returnentity; }         PublicIqueryable<t> getentities (Expression<func<t,BOOL>>where)        {            return_context. Set<t> (). Where (where); }         Public intSaveChanges () {return_context.        SaveChanges (); }         Public voidDispose () {_context.        Dispose (); }    }

Dalservice

Note that this is just a simple three ways: Add, find, save the database, these three are enough to do a demo, if necessary, please add additional, such as delete, UPDATE, etc.

• Add a database context under Entity MyContext.cs

 public  class   Mycontext:dbcontext { public  mycontext (): base   () {}  publ IC  mycontext (dbcontextoptions<mycontext> options):  base   (options) {}  override  protected  void   onconfiguring (Dbcontextoptionsbuilder optionsbuilder) { 
    
     base  
     
    

Mycontext

　

5. Add a BLL layer file

• Under the BLL-Interfaces folder, add the interface IBllService.cs

     Public Interface where class New ()    {        bool  issave);        IQueryableboolwhere);         int SaveChanges ();    }

Ibllservice

• Under the BLL-Implements folder, add the base class BllService.cs

    /// <summary>    ///Data Logic layer: BLL/// </summary>    /// <typeparam name= "T" ></typeparam>     Public classBllservice<t>: ibllservice<t>whereT:class,New()    {        /// <summary>        ///Database Services/// </summary>        protectedIdalservice<t>_dal;  PublicBllservice (idalservice<t>dal) {_dal=dal; }         PublicT addentity (t entity,BOOLIssave) {Entity=_dal.            Addentity (entity); if(issave) {if(SaveChanges () >0)                    return NULL; }            returnentity; }         PublicIqueryable<t> getentities (Expression<func<t,BOOL>>where)        {            return_dal. Getentities (where); }         Public intSaveChanges () {return_dal.        SaveChanges (); }    }

Bllservice

6. Finally, in Startup.cs, add the dependency mappings.

         Public void configureservices (iservicecollection services)        {            diregister (services);            Services. Addmvc ();        }         // Configuring Dependency Injection mapping Relationships         Public void Diregister (iservicecollection services)        {            services. AddTransient (typeoftypeof(dalservice<>));        }

Startup

After all the steps are complete, the solution directory is as follows

　　

So far, the three-tier architecture has all been completed. In the next chapter, we will use the MySQL database, based on this three-tier framework, to develop dbfirst based on EF core.

Based on ASP. 2.0 WebAPI Background Framework (1)-Dependency injection three-layer frame construction