更新

NLogStudy.CoreWeb2.Default/Controllers/ValuesController.cs

@@ -3,18 +3,24 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc;
-
+using Microsoft.Extensions.Logging;
 namespace NLogStudy.CoreWeb2.Default.Controllers
 {
     [Route("api/[controller]")]
     [ApiController]
     public class ValuesController : ControllerBase
     {
+        private readonly ILogger logger;
+        public ValuesController(ILogger<ValuesController> logger)
+        {
+            this.logger = logger;
+        }
+
         // GET api/values
         [HttpGet]
         public ActionResult<IEnumerable<string>> Get()
         {
-            
+            logger.LogCritical("测试警钟长鸣");
             return new string[] { "value1", "value2" };
         }
 

NLogStudy.CoreWeb2.Default/Document/使用NLog.md

@@ -0,0 +1,100 @@
+# ASP.NET Core 2.x 使用Nlog
+## 第一步
+> 创建一个 ASP.NET Core 2.ｘ 项目
+
+## 第二步
+  > 添加nuget包
+
+  > + NLog 
+  > + NLog.Web.AspNetCore 
+  > + NLog.Extensions.Logging
+
+## 第三步
+  > 根目录创建配置文件 nlog.config, 至少配置一项Target和一项Rules
+
+## 第四步
+ > 配置文件属性配置为"复制到输出目录"
+
+## 第五步
+> 更新 program.cs
+
+``` csharp
+using NLog.Web;
+using Microsoft.Extensions.Logging;
+
+public static void Main(string[] args)
+{
+    // NLog: setup the logger first to catch all errors
+    var logger = NLog.Web.NLogBuilder.ConfigureNLog("nlog.config").GetCurrentClassLogger();
+    try
+    {
+        logger.Debug("init main");
+        CreateWebHostBuilder(args).Build().Run(); 
+    }
+    catch (Exception ex)
+    {
+        //NLog: catch setup errors
+        logger.Error(ex, "Stopped program because of exception");
+        throw;
+    }
+    finally
+    {
+        // Ensure to flush and stop internal timers/threads before application-exit (Avoid segmentation fault on Linux)
+        NLog.LogManager.Shutdown();
+    }
+}
+
+public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
+    WebHost.CreateDefaultBuilder(args)
+        .UseStartup<Startup>()
+        .ConfigureLogging(logging =>
+        {
+            logging.ClearProviders();
+            logging.SetMinimumLevel(Microsoft.Extensions.Logging.LogLevel.Trace);
+        })
+        .UseNLog();  // NLog: setup NLog for Dependency injection
+```
+
+## 第六步
+> 配置 appsettings.json 
+
+> 在appsettings.json中指定的日志配置将覆盖对setminimumlevel的任何调用。所以要么去掉“默认”：要么根据你的需要调整它。
+
+``` json
+{
+    "Logging": {
+        "LogLevel": {
+            "Default": "Trace",
+            "Microsoft": "Information"
+        }
+    }
+}
+```
+> 记住还要更新任何特定于环境的配置，以避免任何意外。例如：appsettings.development.json
+
+## 第七步
+> 写日志：在controller中，注入 ILogger
+
+```csharp
+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("Index page says hello");
+        return View();
+    }
+}
+```
+
+## 第八步
+
+> 查看日志

NLogStudy.CoreWeb2.Default/NLogStudy.CoreWeb2.Default.csproj

@@ -8,6 +8,11 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.App" />
     <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="2.2.0" PrivateAssets="All" />
+    <PackageReference Include="NLog" Version="4.6.7" />
+    <PackageReference Include="NLog.Config" Version="4.6.7" />
+    <PackageReference Include="NLog.Extensions.Logging" Version="1.6.1" />
+    <PackageReference Include="NLog.Schema" Version="4.6.7" />
+    <PackageReference Include="NLog.Web.AspNetCore" Version="4.9.0" />
   </ItemGroup>
 
 </Project>

NLogStudy.CoreWeb2.Default/Program.cs

@@ -7,6 +7,7 @@ using Microsoft.AspNetCore;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Logging;
+using NLog.Web;
 
 namespace NLogStudy.CoreWeb2.Default
 {
@@ -19,6 +20,12 @@ namespace NLogStudy.CoreWeb2.Default
 
         public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
             WebHost.CreateDefaultBuilder(args)
-                .UseStartup<Startup>();
+                    .UseStartup<Startup>()
+                    .ConfigureLogging((hostBuild, loggerBuild) =>
+                    {
+                        loggerBuild.ClearProviders();
+                        loggerBuild.SetMinimumLevel(Microsoft.Extensions.Logging.LogLevel.Trace);
+                    })
+                    .UseNLog();
     }
 }