using log4net.Layout;
using log4net.Layout.Pattern;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;

namespace Lskj.Util
{
    public class MyLayout : PatternLayout
    {

        public MyLayout()
        {

            this.AddConverter("property", typeof(MyPatternConverter));

        }

    }


    public class MyPatternConverter : PatternLayoutConverter
    {

        protected override void Convert(System.IO.TextWriter writer, log4net.Core.LoggingEvent loggingEvent)
        {

            if (Option != null)
            {

                WriteObject(writer, loggingEvent.Repository, LookupProperty(Option, loggingEvent));

            }
            else
            {
                // 写入所有关键值对

                WriteDictionary(writer, loggingEvent.Repository, loggingEvent.GetProperties());

            }

        }


        /// <summary>
        /// 通过反射获取传入的日志对象的某个属性的值
        /// </summary>
        /// <param name="property"></param>
        /// <param name="loggingEvent"></param>
        /// <returns></returns>
        private object LookupProperty(string property, log4net.Core.LoggingEvent loggingEvent)
        {
            object propertyValue = default(object);
            PropertyInfo propertyInfo = null;
            Type objtype = loggingEvent.MessageObject.GetType();
            propertyInfo = objtype.GetProperty(property);

            propertyValue = propertyInfo != null ? propertyInfo.GetValue(loggingEvent.MessageObject, null) : loggingEvent.LookupProperty(property);
            if (property == "msg" && objtype == typeof(String))
            {
                return loggingEvent.MessageObject;
            }

            return propertyValue ?? "";

        }

    }
}