How do I add a custom logger which is injected to the Program class of a ASP.NET Core WebApi project?
The WebApi is hosted inside a WinForms App which I want to utilize for logging.,

WebApi Project:

public class Program
{
    public IHost ApiHost { get; private set; }
    public Task ServerTask { get; private set; }

    public async Task Main(string[] args, CancellationToken token, ILogger logger)
    {
        ApiHost = CreateHostBuilder(args).Build();
        ServerTask = ApiHost.RunAsync(token);
        await ServerTask;
    }

    public IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseStartup<Startup>();
            })
        .ConfigureLogging( // how to add my logger here?            
    }
}

WinForms Logger:

public class UILogger : ILogger
{
    private readonly UILoggerProvider _provider;

    public UILogger(UILoggerProvider provider)
    {
        _provider = provider;
    }

    public IDisposable BeginScope<TState>(TState state)
    {
        return null;
    }

    public bool IsEnabled(LogLevel logLevel)
    {
        return logLevel != LogLevel.None;
    }

    public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
    {
        var logRecord = string.Format("{0} [{1}] {2} {3}", "["   DateTimeOffset.UtcNow.ToString("yyyy-MM-dd HH:mm:ss 00:00")   "]", logLevel.ToString(), formatter(state, exception), exception != null ? exception.StackTrace : "");
        if(_provider.Options.LogControl != null)
        {
            var ctl = _provider.Options.LogControl;
            ctl.Invoke((MethodInvoker)(() =>
               {
                   ctl.AppendText(logRecord);
               }));
        }
    }
}

public class UILoggerOptions
{
    public RichTextBox LogControl { get; set; }
}

public class UILoggerProvider : ILoggerProvider
{
    public readonly UILoggerOptions Options;

    public UILoggerProvider(UILoggerOptions options)
    {
        Options = options;
    }

    public ILogger CreateLogger(string categoryName)
    {
        return new UILogger(this);
    }

    public void Dispose()
    {

    }
}

CodePudding user response：

Used the AddProvider extension method and inject the UILoggerProvider

public class Program
{
    public IHost ApiHost { get; private set; }
    public Task ServerTask { get; private set; }
    private ILoggerProvider provider;

    public async Task Main(string[] args, CancellationToken token, ILoggerProvider loggerProvider)
    {
        provider = loggerProvider;
        ApiHost = CreateHostBuilder(args).Build();
        ServerTask = ApiHost.RunAsync(token);
        await ServerTask;
    }

    public IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseStartup<Startup>();
            })
        .ConfigureLogging(builder =>
        {
            builder.ClearProviders();
            builder.AddProvider(provider);
        });       
}