C＃-使用NLog记录自定义异常

Question

我正在尝试将NLog配置为将我自己的异常和系统异常记录到2个不同的日志文件中。假设我运行_logger.LogError("This is my exception.")时，应该将其记录到myerrors.log，但是当服务器崩溃时，该错误应记录到另一个文件中。我现在遇到的问题是，系统错误已记录到两个文件中。这是我的nlog.config文件：

<?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=".\SystemLogs\internal-nlog.txt">

  <!-- enable asp.net core layout renderers -->
  <extensions>
    <add assembly="NLog.Web.AspNetCore"/>
  </extensions>

  <!-- the targets to write to -->
  <targets>
    <!-- write logs to file  -->
    <target xsi:type="File" name="allfile" fileName=".\SystemLogs\nlog-all-${shortdate}.log"
            layout="${longdate}|${event-properties:item=EventId_Id}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}" />

    <!-- another file log, only own logs. Uses some ASP.NET core renderers -->
    <target xsi:type="File" name="ownFile-web" fileName=".\ErrorLogs\${shortdate}\errors-${shortdate}.log"
            layout="${longdate}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}|url: ${aspnet-request-url}|action: ${aspnet-mvc-action}" />
  </targets>

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

    <!--Skip non-critical Microsoft logs and so log only own logs-->
    <logger name="Microsoft.*" maxlevel="Info" final="true" />
    <!-- BlackHole without writeTo -->
    <logger name="*" minlevel="Error" writeTo="ownFile-web" />
  </rules>
</nlog>

这是appsettings.json配置：

"Logging": {
    "IncludeScopes": false,
    "LogLevel": {
      "Default": "Error",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  }

Answer 1

首先，您需要配置一个全局异常处理机制，该机制可以处理任何未处理的异常。

在.Net Core中，您可以通过创建中间件参考link来做到这一点。

public class ExceptionMiddleware
{
    private readonly RequestDelegate _next;
    private readonly ILogger<ExceptionMiddleware> _logger;

    public ExceptionMiddleware(RequestDelegate next, ILogger<ExceptionMiddleware> logger)
    {
        _logger = logger;
        _next = next;
    }

    public async Task InvokeAsync(HttpContext httpContext)
    {
        try
        {
            await _next(httpContext);
        }
        catch (Exception ex)
        {
            _logger.Error(ex);
            await HandleExceptionAsync(httpContext, ex);
        }
    }

    private Task HandleExceptionAsync(HttpContext context, Exception exception)
    {
        context.Response.ContentType = "application/json";
        context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;

        ApiResponse<object> response = new ApiResponse<object>(exception, EResponseCode.GlobalException, exception.Message, null);

        string responseString = JsonConvert.SerializeObject(response);
        return context.Response.WriteAsync(responseString);
    }
}

然后，通过Startup.cs将其注册到app.UseMiddleware<ExceptionMiddleware>();中>

创建一个名为globalErrors的目标。

<target xsi:type="File" name="globalErrors" fileName="\globalErrors.log"
        layout="${longdate}|${event-properties:item=EventId_Id}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}" />
配置来自中间件的日志。

<logger name="*.ExceptionMiddleware" writeTo="globalErrors" />