Cannot add Microsoft.Extensions.Logging.EventLog package with .NET Core 2 application

Question

so as per the MS documentation we can add EvventLog as one of the logging provider. However when i add Microsoft.Extensions.Logging.EventLog package in my .NET Core 2 Web Api application i see yellow explaination mark like below

With such warning i was still able to add EventLog in BuildWebHost method

public static IWebHost BuildWebHost(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseStartup<Startup>()
                .UseApplicationInsights()
                .UseUrls("http://*:40006")                
            .ConfigureLogging((hostingContext,logging)=> 
            {
                logging.AddEventLog(new Microsoft.Extensions.Logging.EventLog.EventLogSettings()
                {                    
                    SourceName = "MySource",
                });
            })
            .Build();

however when i run the application i get error

Could not load type 'System.Diagnostics.EventLog' from assembly 'System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.'

and Warning

Severity Code Description Project File Line Suppression State Warning NU1701 Package 'Microsoft.Extensions.Logging.EventLog 2.0.0' was restored using '.NETFramework,Version=v4.6.1' instead of the project target framework '.NETCoreApp,Version=v2.0'. This package may not be fully compatible with your project.

I have heard somebody from Microsoft mention that Event logging will be included in an extension pack delivered in .Net Core 2.1. There is also an earlier Stackoverflow question on the same subject https://stackoverflow.com/questions/39131217/write-to-eventlog-in-net-core — JRB, Mar 05 '18 at 23:55

score 0 · Answer 1 · answered Mar 06 '18 at 02:08

I've had some success with this in .NET Core 2.x:

using System;
using System.Runtime.InteropServices;

namespace Foo
{
    public enum EventLogType
    {
        EVENTLOG_SUCCESS = 0x000,
        EVENTLOG_AUDIT_FAILURE = 0x0010,
        EVENTLOG_AUDIT_SUCCESS = 0x0008,
        EVENTLOG_ERROR = 0x0001,
        EVENTLOG_INFORMATION = 0x0004,
        EVENTLOG_WARNING = 0x0002
    }

    public static class EventLog
    {
        [DllImport("advapi32.dll", EntryPoint = "RegisterEventSource", SetLastError = true)]
        public static extern long RegisterEventSource(string lpUNCServerName, string lpSourceName);

        [DllImport("advapi32.dll", EntryPoint = "DeregisterEventSource", SetLastError = true)]
        public static extern int DeregisterEventSource(IntPtr hHandle);

        [DllImport("advapi32.dll", SetLastError = true)]
        static extern int ReportEvent(IntPtr hHandle, ushort wType, ushort wCategory, uint dwEventID, IntPtr uSid, ushort wStrings, uint dwDataSize, string[] lpStrings, byte bData);

        public static void Write(string source, string message, EventLogType type)
        {
            int lastError = -1;
            IntPtr handle = IntPtr.Zero;
            string[] strs = new string[2];

            long rawHandle64 = RegisterEventSource(null, source);
            handle = new IntPtr(rawHandle64);

            lastError = Marshal.GetLastWin32Error();

            if (lastError == 0)
            {
                strs[0] = source;
                strs[1] = message;

                int res = ReportEvent(handle, (ushort)type, 0, 0, IntPtr.Zero, 2, 0, strs, 0);

                lastError = Marshal.GetLastWin32Error();

                DeregisterEventSource(handle);

                lastError = Marshal.GetLastWin32Error();
            }
        }
    }
}

i will wait..:) even i serilog.sinks.eventlog does not work with .NET Core 2 — LP13, Mar 06 '18 at 04:22

score 0 · Answer 2 · answered Oct 01 '18 at 19:33

0

If using 2.0 you'll need to add a reference to package Microsoft.Windows.Compatibility as described in ASP.NET Core and Windows Event Log.

answered Oct 01 '18 at 19:33

Mark G

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Cannot add Microsoft.Extensions.Logging.EventLog package with .NET Core 2 application

2 Answers2