.Net Core WebApi(1)— 入门

主要讲述利用EF Core的CodeFirst迁移数据库，简单接口增删改查的使用，利用Swagger生成接口文档。

1.新建项目 创建DbContext 和实体模型

 

（1）添加类ToDoDbContext，继承DbContext

    public class ToDoContext:DbContext
    {
        public ToDoContext(DbContextOptions<ToDoContext> options) : base(options)
        {
        }
        public DbSet<ToDoItem> ToDoItems { get; set; }
    }

(2) 添加类 ToDoItem

    public class ToDoItem
    {
        //自增标识
        public int ID { get; set; }
        /// <summary>
        /// 名称
        /// </summary>
        public string Name { get; set; }
        /// <summary>
        /// 是否完成
        /// </summary>
        public bool IsCompleted { get; set; }
    }

 

2.CodeFirst-数据库迁移 

(1)在“appsettings.json”中，配置数据库连接字符串

  "ConnectionStrings": {
     "todoContext": "Server=.;DataBase=ToDoDataBase;uid=sa;pwd=密码"
  },

（2）在启动项“Startup.cs”中 添加映射关系

 public void ConfigureServices(IServiceCollection services)
        {
            services.AddDbContext<ToDoContext>(opt =>  opt.UseSqlServer(Configuration.GetConnectionString("todoContext")));
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
        }

（3）通过程序包控制台 数据库迁移

首先 导入Nuget包 Install-Package Microsoft.EntityFrameworkCore.Tools

然后 执行              Add-Migration InitDatabase

最后更新数据库    update-database

 

所有步骤后会在项目中生成一个新的Migrations文件

 

 

3.完成增删改查接口

 添加 空的Webapi控制器 ToDoController

 

  [Route("[controller]")]
    public class ToDoController : ControllerBase
    {
        private readonly ToDoContext context;
        //构造函数 初始化
        public ToDoController(ToDoContext context)
        {
            this.context = context;
            if (this.context.ToDoItems.Count() == 0)
            {
                this.context.ToDoItems.Add(new ToDoItem { Name = "Item1" });
                this.context.SaveChanges();
            }
        }
        //默认
        [HttpGet]
        public IEnumerable<ToDoItem> GetAll()
        {
            return context.ToDoItems.ToList();
        }
        [HttpGet("{id}",Name ="GetTodo")]
        /// <summary>
        /// 根据Id获取
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        public IActionResult GetById(long id)
        {
            var item = context.ToDoItems.FirstOrDefault();
            if (item == null)
            {
                return NotFound();
            }
            return new ObjectResult(item);
        }
        /// <summary>
        /// 新增
        /// </summary>
        /// <param name="item"></param>
        /// <returns></returns>
        [HttpPost]
        public IActionResult Create([FromBody] ToDoItem item)
        {
            if (item == null)
            {
                return BadRequest();
            }
            context.ToDoItems.Add(item);
            context.SaveChanges();
            return CreatedAtRoute("GetTodo", new { id = item.ID }, item);
        }
        /// <summary>
        /// 更新
        /// </summary>
        /// <param name="id"></param>
        /// <param name="item"></param>
        /// <returns></returns>
        [HttpPut("{id}")]
        public IActionResult Update(long id, [FromBody] ToDoItem item)
        {
            if (item == null && item.ID != id)
            {
                return BadRequest();
            }
            var model = context.ToDoItems.SingleOrDefault(t => t.ID == id);
            if (model == null)
            {
                return NotFound();
            }
            model.IsCompleted = item.IsCompleted;
            model.Name = item.Name;
            context.ToDoItems.Update(model);
            context.SaveChanges();
            return NoContent();
        }
        /// <summary>
        /// 删除
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        [HttpDelete("{id}")]
        public IActionResult Delete(long id)
        {
            var todo = context.ToDoItems.FirstOrDefault(t => t.id == id);
            if (todo == null)
            {
                return NotFound();
            }
            context.ToDoItems.Remove(todo);
            context.SaveChanges();
            return new NoContentResult();
        }
    }

4.swagger接口文档生成 

Install-Package Swashbuckle.AspNetCore

 

（1）在“Startup.cs”中对swagger注入

public void ConfigureServices(IServiceCollection services)
        {
            //swagger 配置
            services.AddSwaggerGen(c =>
            {
                var xmlFile = $"{Assembly.GetExecutingAssembly().GetName().Name}.XML";
                var xmlPath = Path.Combine(AppContext.BaseDirectory, xmlFile);
                c.SwaggerDoc("v1", new Info { Title = "My API", Version = "v1" });
            });
            services.AddDbContext<ToDoContext>(opt =>  opt.UseSqlServer(Configuration.GetConnectionString("todoContext")));
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
        }
        /// <summary>
        /// 管道配置
        /// </summary>
        /// <param name="app"></param>
        /// <param name="env"></param>
        // This method gets called by the runtime. Use this method to configure the HTTP  request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                // The default HSTS value is 30 days. You may want to change this for  production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }
            app.UseHttpsRedirection();
            app.UseMvc();
            // Enable middleware to serve generated Swagger as a JSON endpoint.
            //启用中间件服务生成Swagger作为JSON终结点
            app.UseSwagger();
            // Enable middleware to serve swagger-ui (HTML, JS, CSS, etc.), specifying the  Swagger JSON endpoint.
            ////启用中间件服务对swagger-ui，指定Swagger JSON终结点
            app.UseSwaggerUI(c =>
            {
                c.ShowExtensions();
                
                c.SwaggerEndpoint("/swagger/v1/swagger.json", "test V1");
            });
         
        }
 

 

（2）右击项目，选择“属性”，勾选“XML文档文件”，带出文档的注释

 

（3）运行程序，访问swagger，能够看到所有接口的说明，并进行接口调试