Filtering events via ByIncludingOnly

Question

I've got a situation where some log events contain large property values (in this particular case, a large packet of XML). I want to use Serilog's ByIncludingOnly functionality to use an additional sink for these large data events. Here's a sample of what I thought would work:

    private static void FilteredLogging()
    {
        Log.Logger = new LoggerConfiguration()
            .WriteTo.Console(new RawFormatter())
            .WriteTo.Logger(lc => lc.Filter.ByIncludingOnly(LargeDataPackets))
                .WriteTo.File("big.txt")
            .CreateLogger();

        Log.Information("go");
        Log.ForContext("data", "12345").Information("Small packet");
        Log.ForContext("data", "1234567890987654321").Information("Big packet");

        Log.CloseAndFlush();
    }

    private static bool LargeDataPackets(LogEvent le)
    {
        return le.Properties.ContainsKey("data") &&
               le.Properties["data"].ToString().Length > 10;
    }

However, when I run this code, all three messages go to the "big.txt" file. I would expect only the last item ("Big packet") to go to the file since it's the only event with a data property that is over 10 characters.

I'm using Serilog 2.0.

Answer 1

您的括号稍微偏离：

    Log.Logger = new LoggerConfiguration()
        .WriteTo.Console(new RawFormatter())
        .WriteTo.Logger(lc => lc.Filter.ByIncludingOnly(LargeDataPackets))
            .WriteTo.File("big.txt")
        .CreateLogger();

应该是：

    Log.Logger = new LoggerConfiguration()
        .WriteTo.Console(new RawFormatter())
        .WriteTo.Logger(lc => lc.Filter.ByIncludingOnly(LargeDataPackets)
            .WriteTo.File("big.txt"))
        .CreateLogger();