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:
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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:
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上述业务的电视剧的增删改就会出现这种情况:
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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:
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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:
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然后调用AfterMap方法做后期手动处理, 代码的意思大概是这样:
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或者, 也可以用Linq做一些重构:
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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:
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