使用log4net记录日志到数据库（含自定义属性）
日志输出自定义属性！ 特来总结一下：
一、配置文件
使用log4写入数据库就不多说了，网上方法很多，自定义字段如下
1 <commandText value="INSERT INTO dbo.AppLog (dtDate,sThread,sLevel,sLogger,sMessage,sException,ip,url) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception,@userIP,@url)" />
1 <parameter>
2 <parameterName value="@userIP" />
3 <dbType value="String" />
4 <size value="50" />
5 <layout type="NNAppServer.Common.MyLayout" >
6 <conversionPattern value = "%property{userIP}"/>
7 </layout>
8 </parameter>
NNAppServer.Common.MyLayout 是要自定义类的命名空间
二、自定义类
新建 MyCustomer 类 ，注意命名空间和配置文件一致
1 public class MyCustomer
2 {
3 public MyCustomer(string userIP, string url)
4 {
5 this._userIP = userIP;
6 this._url = url;
7 }
8
9 private string _userIP;
10
11 /// <summary>
12 /// 用户IP
13 /// </summary>
14 public string userIP
15 {
16 get { return _userIP; }
17 set { _userIP = value; }
18 }
19
20 private string _url;
21
22 /// <summary>
23 /// 路径
24 /// </summary>
25 public string url
26 {
27 get { return _url; }
28 set { _url = value; }
29 }
30 }
31
32 class MyLayout : PatternLayout
33 {
34 public MyLayout()
35 {
36 this.AddConverter("property", typeof(MyMessagePatternConverter));
37 }
38 }
39
40 class MyMessagePatternConverter : PatternLayoutConverter
41 {
42 protected override void Convert(System.IO.TextWriter writer, log4net.Core.LoggingEvent loggingEvent)
43 {
44 if (Option != null)
45 {
46 // Write the value for the specified key
47 WriteObject(writer, loggingEvent.Repository, LookupProperty(Option, loggingEvent));
48 }
49 else
50 {
51 // Write all the key value pairs
52 WriteDictionary(writer, loggingEvent.Repository, loggingEvent.GetProperties());
53 }
54 }
55
56 private object LookupProperty(string property, log4net.Core.LoggingEvent loggingEvent)
57 {
58 object propertyValue = string.Empty;
59
60 var pi = loggingEvent.MessageObject.GetType().GetProperty(property);
61
62 if (pi != null)
63 propertyValue = pi.GetValue(loggingEvent.MessageObject, null);
64
65 return propertyValue;
66 }
三、新建一个异常过滤器，将要获取的字段写入
public class MyExceptionAttribute : IExceptionFilter
{
public void OnException(ExceptionContext filterContext)
{
var ex = filterContext.Exception;
var ip = Common.ComHelper.GetIP();
string url = filterContext.HttpContext.Request.RawUrl;
LogHelper.Error(new MyCustomer(ip, url), ex);
}
}
参考文档： http://www.cnblogs.com/goody9807/archive/2010/10/29/1864581.html
处理webApi： 1、自定义一个类，继承ExceptionFilterAttribute，重写OnException方法 和mvc差不多
2、在 WebApiConfig.cs 文件的 Register方法里面添加 config.Filters.Add(new WebApiExceptionFilterAttribute())
https://www.cnblogs.com/landeanfen/p/5363846.html
http://blog.sina.com.cn/s/blog_72463843010195ru.html
空合并运算符【 ?? 】为右结合运算符，即操作时从右向左进行组合的
