.net core试水

概述

大概记录下我如何第一次使用.net core搭建一个api，由于最近.net core比较火，我也尝试着使用.net core做了一个小功能

本文主要包括

1.环境配置

2.程序编写

3.程序部署

主要参考：https://docs.microsoft.com/zh-cn/aspnet/core/tutorials/first-web-api?view=aspnetcore-3.1&tabs=visual-studio

1、环境配置

想要使用.net core3.1 第一个问题是更新VS，更新过程中遇到报错

VS_InstallerShell.exe has an invalid certificate. Please ensure the appropriate Microsoft certificates are installed

网上很多方法试过没有效果，最后在哪里（自己也忘记了）找到了解决方案，安装两个windows补丁，附上补丁编号和下载地址

https://www.catalog.update.microsoft.com/Home.aspx

KB4474419
kb4490628

2.程序编写

安装了最新vs以后，点击新建项目，创建3.1 .net core API项目，创建以后可以直接运行，会有一个天气预报的示例

使用Nuget安装Microsoft.EntityFrameworkCore.SqlServr，ef我虽然没有在实际项目中使用过，不过陆陆续续知道点，今天顺便试试

2.1 创建数据库上下文类

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.Data.SqlClient;
 using Microsoft.EntityFrameworkCore;

 namespace reportAPI
 {
     public class ChartDesignContenxt: DbContext
     {
         protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
         {
             var sqlConnectionStringBuilder = new SqlConnectionStringBuilder
             {
                 DataSource = "*.*.*.*",
                 InitialCatalog = "*",
                 UserID = "sa",
                 Password = ""
             };
             optionsBuilder.UseSqlServer(sqlConnectionStringBuilder.ConnectionString);

             base.OnConfiguring(optionsBuilder);
         }
         public DbSet<chartDesign> chartDesigns { get; set; }
     }
 }

2.2 在startup.cs类中注入数据库上下文类，添加跨域配置

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.HttpsPolicy;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;

 namespace reportAPI
 {
     public class Startup
     {
         public Startup(IConfiguration configuration)
         {
             Configuration = configuration;
         }

         public IConfiguration Configuration { get; }

         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {
             //允许一个或多个具体来源:
             services.AddCors(options =>
             {
                 // 配置跨域
                 options.AddPolicy("cors", policy =>
                 {
                     // 设定允许跨域的来源，有多个的话可以用 `,` 隔开
                     policy
                             .AllowAnyOrigin()
                             .AllowAnyHeader()
                             .AllowAnyMethod();
                 });
             });

             services.AddScoped<IPMSDbContenxt>(_ => new IPMSDbContenxt());
             services.AddScoped<ChartDesignContenxt>(_ => new ChartDesignContenxt());   //注入数据库上下文类

             services.AddControllers();
         }

         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
         public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
         {
             if (env.IsDevelopment())
             {
                 app.UseDeveloperExceptionPage();
             }

             app.UseHttpsRedirection();

             app.UseRouting();

             app.UseCors("cors");  //使用跨域

             app.UseAuthorization();

             app.UseEndpoints(endpoints =>
             {
                 endpoints.MapControllers();
             });
         }
     }
 }

2.3 创建控制器，一共三个方法，获取列表，更新一条记录，获取一条记录

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;

 namespace reportAPI.Controllers
 {
     [Route("api/[controller]/[action]")]
     [ApiController]
     public class ChartDesignController : ControllerBase
     {
         private readonly ChartDesignContenxt _context;

         public ChartDesignController(ChartDesignContenxt context)
         {
             _context = context;
         }

         [HttpPost]
         public IActionResult Save(CommonFilter filter)
         {
             try
             {
                 //var temp = entity.data.ToString();
                 chartDesign model = new chartDesign();
                 model.designName = filter.field1;
                 model.designContent = filter.data.ToString();
                 if (filter.key == -)
                 {
                     _context.Add<chartDesign>(model);
                 }
                 else
                 {
                     model.designId = filter.key;
                     _context.Update<chartDesign>(model);
                 }
                 _context.SaveChanges();
                 return Ok("保存成功");
             }
             catch(Exception ex)
             {
                 return Ok(ex.Message);
             }

         }
         [HttpPost]
         public IActionResult Get(CommonFilter filter)
         {
             try
             {
                 chartDesign entity = _context.chartDesigns.Find(filter.key);
                 if (entity == null)
                 {
                     return NotFound();
                 }

                 return Ok(entity);
             }
             catch(Exception ex)
             {
                 return Ok(ex.Message);
             }
         }
         [HttpPost]
         public IActionResult GetList()
         {
             try
             {
                 string sql = "select * from chartDesign";
                 List<chartDesign> list = _context.chartDesigns.ToList(); //.FromSqlRaw(sql).ToList();
                 return Ok(list);
             }
             catch (Exception ex)
             {
                 return Ok(ex.Message);
             }
         }
     }
 }

一个增删改完成

3.部署到服务器

部署比较简单，直接拷贝bin下面的内容，然后双击  项目名.exe 服务就启动起来了