.Net core 基础 创建及Nlog

一、.Net Core 依赖注入

1. .net core3.1 之前的版本需要手动配置swagger。当前项目.net core5.0版本自动配置完成

2. 跨域配置

   1.下载依赖包

   2.

              //跨域
               services.AddCors(options =>
               {
                   options.AddDefaultPolicy(c =>
                   {
                       //AllowAnyOrigin 来源  AllowAnyMethod 方法  AllowAnyHeader头部信息
                       c.AllowAnyOrigin().AllowAnyMethod().AllowAnyHeader();

​ }); ​ });

3.使用跨域 在路由之后 授权之前

              //路由
               app.UseRouting();
               //使用跨域！！！！
               app.UseCors();
               //授权
               app.UseAuthorization();

1. 迁移命令：

   1.add-migration inir

   2.update-database

2. 不使用驼峰命名规范

   services.AddControllers().AddJsonOptions(options => options.JsonSerializerOptions.PropertyNamingPolicy = null);

3. NLog配置

   安装nlog包

   2、在项目根部创建 nlog.config（全部小写）文件。

   3、使用实例

   <?xml version="1.0" encoding="utf-8" ?>
   <nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         autoReload="true"
         internalLogLevel="Info"
         internalLogFile="c:\temp\internal-nlog-AspNetCore.txt">
   ​
     <!-- enable asp.net core layout renderers -->
     <extensions>
       <add assembly="NLog.Web.AspNetCore"/>
     </extensions>
   ​
     <!-- the targets to write to -->
     <targets>
       <!-- File Target for all log messages with basic details -->
       <target xsi:type="File" name="allfile" fileName="c:\temp\nlog-AspNetCore-all-${shortdate}.log"
               layout="${longdate}|${event-properties:item=EventId_Id:whenEmpty=0}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}" />
   ​
       <!-- File Target for own log messages with extra web details using some ASP.NET core renderers -->
       <target xsi:type="File" name="ownFile-web" fileName="c:\temp\nlog-AspNetCore-own-${shortdate}.log"
               layout="${longdate}|${event-properties:item=EventId_Id:whenEmpty=0}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}|url: ${aspnet-request-url}|action: ${aspnet-mvc-action}|${callsite}| body: ${aspnet-request-posted-body}" />
   ​
       <!--Console Target for hosting lifetime messages to improve Docker / Visual Studio startup detection -->
       <target xsi:type="Console" name="lifetimeConsole" layout="${level:truncate=4:lowercase=true}: ${logger}[0]${newline}      ${message}${exception:format=tostring}" />
     </targets>
   ​
     <!-- rules to map from logger name to target -->
     <rules>
       <!--All logs, including from Microsoft-->
       <logger name="*" minlevel="Trace" writeTo="allfile" />
   ​
       <!--Output hosting lifetime messages to console target for faster startup detection -->
       <logger name="Microsoft.Hosting.Lifetime" minlevel="Info" writeTo="lifetimeConsole, ownFile-web" final="true" />
   ​
       <!--Skip non-critical Microsoft logs and so log only own logs (BlackHole) -->
       <logger name="Microsoft.*" maxlevel="Info" final="true" />
       <logger name="System.Net.Http.*" maxlevel="Info" final="true" />
       
       <logger name="*" minlevel="Trace" writeTo="ownFile-web" />
     </rules>
   </nlog>

   4、更新程序.cs 对比原代码粘贴新代码

   using NLog.Web;
   namespace ASP.NET_Core_5_NLog_Example
   {
       public class Program
       {
           public static void Main(string[] args)
           {
               var logger = NLogBuilder.ConfigureNLog("nlog.config").GetCurrentClassLogger();
            
           }
   ​
           public static IHostBuilder CreateHostBuilder(string[] args) =>
               Host.CreateDefaultBuilder(args)
                   .ConfigureWebHostDefaults(webBuilder =>
                   {
                       webBuilder.UseStartup<Startup>();
                   })
                   //！！！！！！复制以下
                   .ConfigureLogging(logging =>
                   {
                       logging.ClearProviders();
                       logging.SetMinimumLevel(LogLevel.Trace);
                   })
                   .UseNLog();  // NLog: Setup NLog for Dependency injection
       }
   }
   ​

   5、配置应用程序安装. json

   {
     "Logging": {
       "LogLevel": {
       ///修改Default 为  Trace
         "Default": "Trace",
         "Microsoft": "Warning",
         "Microsoft.Hosting.Lifetime": "Information"
       }
     },
     "AllowedHosts": "*"
   }

   6、 写日志 将 ILogger 注入控制器：

   using Microsoft.Extensions.Logging;
   ​
   public class HomeController : Controller
   {
       private readonly ILogger<HomeController> _logger;
   ​
       public HomeController(ILogger<HomeController> logger)
       {
           _logger = logger;
   ​
       }
   ​
       public IActionResult Index()
       {
           _logger.LogInformation("测试");
           return View();
       

二、EF Core

1. .net core使用EF core如下

   

2. 引用依赖包 using Microsoft.EntityFrameworkCore;

   当前类继承DBContext 创建上下文

   

   添加上下文

   

   连接数据库