使用Visual Studio Code开发Asp.Net Core WebApi学习笔记（三）-- Logger

第一部分：默认Logger支持

一、project.json添加日志包引用，并在cmd窗口使用 dotnet restore 命令还原包文件。

{
"version": "1.0.0-*",
"buildOptions": {
"debugType": "portable",
"emitEntryPoint": true
},
"dependencies": {
"Microsoft.NETCore.App": {
"type": "platform",
"version": "1.0.0"
},
"Microsoft.AspNetCore.Server.Kestrel": "1.0.0",
"Microsoft.AspNetCore.Mvc": "1.0.0",
"Microsoft.Extensions.Logging": "1.0.0",
"Microsoft.Extensions.Logging.Console": "1.0.0",
"Microsoft.Extensions.Logging.Debug": "1.0.0",
"Microsoft.Extensions.Logging.Filter": "1.0.0"
},
"frameworks": {
"netcoreapp1.0": {
"imports": "dnxcore50"
}
}
}

二、修改Startup.cs文件，添加命令行窗口和调试窗口的日志记录功能。

using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;

namespace WebApiFrame
{
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
// 注入MVC框架
services.AddMvc();
}

public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
{
// 添加日志支持
loggerFactory.AddConsole();
loggerFactory.AddDebug();

// 添加MVC中间件
app.UseMvc();
}
}
}

三、分别使用VS Code的调试功能和命令行的 dotnet run 命令启动程序，浏览器访问 http://localhost:5000/api/users/1 地址后，可以查看到窗口日志打印信息。

第二部分：Logger日志级别

一、修改Startup.cs内容，设置日志级别。

using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;

namespace WebApiFrame
{
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
// 注入MVC框架
services.AddMvc();
}

public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
{
// 添加日志支持

// 设置日志最小级别Warning
loggerFactory.AddConsole(LogLevel.Warning);

//loggerFactory.AddDebug();

// 添加MVC中间件
app.UseMvc();
}
}
}

二、修改UsersController.cs文件内容，添加日志输出。

using System;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using WebApiFrame.Models;

namespace WebApiFrame.Controllers
{

[Route("api/[controller]")]
public class UsersController : Controller
{
private ILogger<UsersController> _logger;

public UsersController(ILogger<UsersController> logger){
_logger = logger;
}

[HttpGet("{id}")]
public IActionResult Get(int id)
{
// 演示日志输出
_logger.LogInformation("This is Information Log!");
_logger.LogWarning("This is Warning Log!");
_logger.LogError("This is Error Log!");

var user = new User() { Id = id, Name = "Name:" + id, Sex = "Male" };
return new ObjectResult(user);
}

[HttpPost]
public IActionResult Post([FromBody] User user){
if(user == null){
return BadRequest();
}

// TODO：新增操作
user.Id = new Random().Next(1, 10);
return CreatedAtAction("Get", new { id = user.Id }, user);
}

[HttpPut("{id}")]
public IActionResult Put(int id, [FromBody] User user){
if(user == null){
return BadRequest();
}

// TODO: 更新操作
return new NoContentResult();
}

[HttpDelete("{id}")]
public void Delete(int id){
// TODO: 删除操作

}
}
}

三、cmd窗口执行 dotnet run 命令，浏览器访问 http://localhost:5000/api/users/1 地址，查看cmd窗口日志输出。

或者，使用Filter设置日志级别，重新执行访问并查看日志输出。

public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
{
// 添加日志支持

// 设置日志最小输出级别为Error
loggerFactory.WithFilter(new FilterLoggerSettings()
{
// 设置以命名空间开头的日志的最小输出级别
{ "Microsoft", LogLevel.Warning },
{ "WebApiFrame", LogLevel.Error }
}).AddConsole();

//loggerFactory.AddDebug();

// 添加MVC中间件
app.UseMvc();
}

第三部分：NLog

一、project.json添加NLog包引用，并使用 dotnet restore 命令还原包文件。

{
"version": "1.0.0-*",
"buildOptions": {
"debugType": "portable",
"emitEntryPoint": true
},
"dependencies": {
"Microsoft.NETCore.App": {
"type": "platform",
"version": "1.0.0"
},
"Microsoft.AspNetCore.Server.Kestrel": "1.0.0",
"Microsoft.AspNetCore.Mvc": "1.0.0",
"Microsoft.Extensions.Logging": "1.0.0",
"Microsoft.Extensions.Logging.Console": "1.0.0",
"Microsoft.Extensions.Logging.Debug": "1.0.0",
"Microsoft.Extensions.Logging.Filter": "1.0.0",
"NLog.Extensions.Logging": "1.0.0-rtm-alpha2"
},
"frameworks": {
"netcoreapp1.0": {
"imports": "dnxcore50"
}
}
}

二、添加NLog配置文件nlog.config。

<?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="Warn"
internalLogFile="internal-nlog.txt">

<!-- define various log targets -->
<targets>
<!-- write logs to file -->
<target xsi:type="File" name="allfile" fileName="nlog-all-${shortdate}.log"
layout="${longdate}|${logger}|${uppercase:${level}}|${message} ${exception}" />

<target xsi:type="File" name="ownFile-web" fileName="nlog-own-${shortdate}.log"
layout="${longdate}|${logger}|${uppercase:${level}}|  ${message} ${exception}" />

<target xsi:type="Null" name="blackhole" />
</targets>

<rules>
<!--All logs, including from Microsoft-->
<logger name="*" minlevel="Trace" writeTo="allfile" />

<!--Skip Microsoft logs and so log only own logs-->
<logger name="Microsoft.*" minlevel="Trace" writeTo="blackhole" final="true" />
<logger name="*" minlevel="Trace" writeTo="ownFile-web" />
</rules>
</nlog>

三、修改Startup.cs文件内容，添加NLog支持。

using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using NLog.Extensions.Logging;

namespace WebApiFrame
{
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
// 注入MVC框架
services.AddMvc();
}

public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
{
// 添加日志支持
//loggerFactory.AddConsole();
//loggerFactory.AddDebug();

// 添加NLog日志支持
loggerFactory.AddNLog();

// 添加MVC中间件
app.UseMvc();
}
}
}

四、重新执行访问并查看日志输出。

第四部分、其他相关内容

public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
{
// 添加日志支持
loggerFactory.AddConsole();
loggerFactory.AddDebug();

// 添加NLog日志支持
loggerFactory.AddNLog();

// 添加MVC中间件
app.UseMvc();
}