第一部分: http://www.cnblogs.com/cgzl/p/8478993.html
第二部分: http://www.cnblogs.com/cgzl/p/8481825.html
由于本文主要是讲VSCode开发等, 所以相关等一些angular/.net core的知识就相对少讲点.
我把需求改一下, 如图:
由于efcore目前还是使用中间表来建立多对多的关系, 所以分类标签这个需求就没什么特别的了, 就去掉吧. 还有电视剧分季这个技术上也是重复的, 也删掉.
目前只剩下电视台和电视剧的维护, 还剩下的知识点是:
- 集合的CRUD操作
- 对项目结构进行整理, 使用Unit Of Work 以及 Repository 模式
- 上传文件
由于CRUD画面做起来比较简单, 我相信大家使用该技术的都会, 所以我直接把我写完的代码传上来. 此时页面的操作效果请看视频:
这时的代码:
https://pan.baidu.com/s/1egCmuNT0OxJNwkz0OQ72kA
这里面又一个比较常见的问题, 就是
针对集合的增删改:
上述业务的电视剧的增删改就会出现这种情况:
数据库里面原来有4条数据, 而前台操作完, 删除了第3条数据, 并且增加了一条数据, 其余数据的内容可能有变化.
这种集合类增删改的思路应该是这样的:
1.从传进来的集合找出所有新添加的数据(新添加的数据Id通常并不存在, 这是条件), 放在一个临时的集合, 然后添加到context.
2.从数据库集合找出所有需要删除的数据(有一些id在传进来的集合找不到的就是), 放在一个集合, 然后从conetxt一次性移除.
3.两个集合都有的数据就是只需要修改内容的数据, 更新即可.
下面开始实现这个功能:
首先确保Put方法里, 把电视台下所有的电视剧都读取出来:
接下来, 找到MappingProfile.cs, 使用AutoMapper来实现这个功能.
首先要忽略默认的集合映射:
然后调用AfterMap方法做后期手动处理, 代码的意思大概是这样:
或者, 也可以用Linq做一些重构:
回到画面试一下编辑功能:
然后添加和删除:
查看结果:
OK.
项目重构
下面, 我们使用Unit Of Work以及Repository Pattern对项目进行重构:
由于这部分也很简单, 并且也不是这篇文章的重点, 我就直接贴出重构后的代码吧:
Database/TvRepostiory.cs:
using System.Collections.Generic; using System.Threading.Tasks; using Microsoft.EntityFrameworkCore; using Tv.Models; namespace Tv.Database { public class TvRepository : ITvRepostitory { private readonly TvContext context; public TvRepository(TvContext context) { this.context = context; } public async Task<List<TvNetwork>> GetTvNetworksAsync() { return await context.TvNetworks.Include(x => x.TvShows).ToListAsync(); } public async Task<TvNetwork> GetTvNetworkByIdAsync(int id, bool includeRelated = true) { if (includeRelated) { return await context.TvNetworks.Include(x => x.TvShows).SingleOrDefaultAsync(x => x.Id == id); } return await context.TvNetworks.FindAsync(id); } public void AddTvNetwork(TvNetwork model) { context.TvNetworks.Add(model); } public void RemoveTvNetwork(TvNetwork model) { context.TvNetworks.Remove(model); } } }
Database/ITvRepository.cs:
using System.Collections.Generic; using System.Threading.Tasks; using Tv.Models; namespace Tv.Database { public interface ITvRepostitory { Task<List<TvNetwork>> GetTvNetworksAsync(); Task<TvNetwork> GetTvNetworkByIdAsync(int id, bool includeRelated = true); void AddTvNetwork(TvNetwork model); void RemoveTvNetwork(TvNetwork model); } }
Database/UnitOfWork.cs:
using System.Threading.Tasks; namespace Tv.Database { public class UnitOfWork : IUnitOfWork { private readonly TvContext context; public UnitOfWork(TvContext context) { this.context = context; } public async Task SaveAsync() { await context.SaveChangesAsync(); } } }
Database/IUnitOfWork.cs:
using System.Threading.Tasks; namespace Tv.Database { public interface IUnitOfWork { Task SaveAsync(); } }
Startup.cs:
public void ConfigureServices(IServiceCollection services) { services.AddAutoMapper(); // services.AddDbContext<TvContext>(opt => opt.UseSqlServer(Configuration["ConnectionStrings:Default"])); services.AddDbContext<TvContext>(opt => opt.UseSqlServer(Configuration.GetConnectionString("Default"))); services.AddScoped<ITvRepostitory, TvRepository>(); services.AddScoped<IUnitOfWork, UnitOfWork>(); services.AddMvc(); }
TvController.cs:
using System.Collections.Generic; using System.Threading.Tasks; using AutoMapper; using Microsoft.AspNetCore.Mvc; using Microsoft.EntityFrameworkCore; using Tv.Database; using Tv.Models; using Tv.ViewModels; namespace Tv.Controllers { public class TvController : Controller { private readonly ITvRepostitory repostiory; private readonly IUnitOfWork unitOfWork; private readonly IMapper mapper; public TvController(ITvRepostitory repostiory, IUnitOfWork unitOfWork, IMapper mapper) { this.repostiory = repostiory; this.unitOfWork = unitOfWork; this.mapper = mapper; } [HttpGet("api/tvnetworks")] public async Task<IEnumerable<TvNetworkViewModel>> GetTvNetworks() { var models = await repostiory.GetTvNetworksAsync(); var vms = mapper.Map<List<TvNetwork>, List<TvNetworkViewModel>>(models); return vms; } [HttpGet("api/tvnetworks/{id}")] public async Task<IActionResult> Get(int id) { var model = await repostiory.GetTvNetworkByIdAsync(id); var vm = mapper.Map<TvNetwork, TvNetworkViewModel>(model); return Ok(vm); } [HttpPost("api/tvnetworks")] public async Task<IActionResult> Post([FromBody]TvNetworkUpdateViewModel vm) { if (!ModelState.IsValid) { return BadRequest(ModelState); } var model = mapper.Map<TvNetworkUpdateViewModel, TvNetwork>(vm); repostiory.AddTvNetwork(model); await unitOfWork.SaveAsync(); var result = mapper.Map<TvNetwork, TvNetworkViewModel>(model); return Ok(result); } [HttpPut("api/tvnetworks/{id}")] public async Task<IActionResult> Put(int id, [FromBody]TvNetworkUpdateViewModel vm) { if (!ModelState.IsValid) { return BadRequest(ModelState); } var dbModel = await repostiory.GetTvNetworkByIdAsync(id); if (dbModel == null) { return NotFound(); } var model = mapper.Map<TvNetworkUpdateViewModel, TvNetwork>(vm, dbModel); await unitOfWork.SaveAsync(); var result = mapper.Map<TvNetwork, TvNetworkViewModel>(model); return Ok(result); } [HttpDelete("api/tvnetworks/{id}")] public async Task<IActionResult> Delete(int id) { var model = await repostiory.GetTvNetworkByIdAsync(id, includeRelated: false); if (model == null) { return NotFound(); } repostiory.RemoveTvNetwork(model); await unitOfWork.SaveAsync(); return NoContent(); } } }
再操作下画面, 没有任何问题.
今天先写到这, VSCode的开发速度还是非常快的.
还剩下最后一部分--上传文件.
下面是我的关于ASP.NET Core Web API相关技术的公众号--草根专栏:
