log4net config file for net.core with UDP Append remote port dynamically

Question

I have a log4net.config file in which I want to be able to inject the RemotePort variable dynamically via Program.cs file. But I am getting the following error :

System.FormatException: Input string was not in a correct format.

I was able to pass RemoteAddress dynamically with this strategy :

log4net config file for net.core with UDP Append remote address dynamically

The code in the log4net file

<appender name="UdpAppender" type="log4net.Appender.UdpAppender">
        <RemoteAddress value="%property{RemoteAddress}" />
        <RemotePort value="%property{RemotePort}" />
        <encoding value="utf-8"/>
        <layout type="log4net.Layout.PatternLayout">
            <conversionPattern value="%date [%thread] %-5level - %property{log4net:HostName} - %message%newline" />
        </layout>
    </appender>

The code in Program.cs

log4net.GlobalContext.Properties["RemotePort"] = 514;

Answer 1

The same concept as shown in the referenced article is also applicable here.

You need a translation from a PatternString to an Int32 which requires a custom type converter implementing IConvertFrom.

Reusing the implementation of a PatternString the %property{RemotePort} will be replaced by the value passed in via log4net.GlobalContext.Properties["RemotePort"] = 514, which will result into 514.

public class NumericConverter : IConvertFrom
{
    public NumericConverter()
    {}

    public Boolean CanConvertFrom(Type sourceType)
    {
        return typeof(String) == sourceType;
    }

    public Object ConvertFrom(Object source)
    {
        String pattern = (String)source;
        PatternString patternString = new PatternString(pattern);
        String value = patternString.Format();

        return Int32.Parse(value);
    }
}

Register this type converter at startup as shown below

log4net.Util.TypeConverters.ConverterRegistry.AddConverter(typeof(int), new NumericConverter());