Exception information provided together with the LogEvent. See alsoHow to properly log exceptions.

Platforms Supported:All

${exception:format=String:innerFormat=String:maxInnerExceptionLevel=Integer:innerExceptionSeparator=String           :separator=String:exceptionDataSeparator=string}

• format - Format of the output. Default:ToString,Data. Must be a comma-separated list of exception properties:

  Notice before NLog 5.0, then default was justmessage.

  • Message - SerializeException.Message
  • Type - SerializeException.GetType().FullName
  • ShortType - SerializeException.GetType().Name
  • ToString - SerializeException.ToString()
  • Method - SerializeException.TargetSite
  • StackTrace - SerializeException.StackTrace
  • Data - Serialize the dictionaryException.Data
  • Source - SerializeException.Source.Introduced in NLog 4.6.7
  • TargetSite - SerializeException.TargetSite.Introduced in NLog 4.6.7
  • HResult - SerializeException.HResult.Introduced in NLog 4.6.8
  • Properties - Appends any additional properties that specific type of Exception might have.Introduced in NLog 4.6.8
  • @ - Serialize all Exception-properties into Json-format.Introduced in NLog 4.5

• innerFormat - Format of the output of inner exceptions. Must be a comma-separated list of exception properties (As shown above). This parameter value is case-insensitive.

• maxInnerExceptionLevel - Maximum number of inner exceptions to include in the output. By default inner exceptions are not enabled for compatibility with NLog 1.0. Note that the format@ serializes InnerException like any other property. Integer. Default: 0

• separator - Separator used to concatenate parts specified in the Format. Default: single space

• innerExceptionSeparator - Separator between inner exceptions. Default: new line

• exceptionDataSeparator - Separator used to concatenate the exception data parts. Default:;

  Introduced in NLog 4.3.9

• baseException - Render innermost Exception from Exception.GetBaseException(). Boolean. Default:false

  Introduced in NLog 4.7.1

• flattenException - Automatically flattenAggregateException from async operations to extract its inner exceptions. Boolean. Default:true

  Introduced in NLog 4.7.6

If debug symbol information is not available, thenException.ToString() will not output source-code filenames or line-numbers. Symbol information from PDB files must be deployed with the application to retrieve and output source-code line-number. For applications compiled in release mode, then inlining can occur and cause "unexpected" line-numbers.

${exception:format=message}

ToString will also print the innerException:

${exception:format=toString}

Also print exception data, e.g.

varex=newException();ex.Data.Add("data1","val2");throwex;

${exception:format=toString,Data}

the@ format recursively serializes the entire exception hierarchy; combining it withmaxInnerExceptionLevel andinnerExceptionSeparator won't do what you want. To get the entire exception hierarchy including innerexceptions as nested objects, just specify:format=@.

${exception:format=@}

NLog 4.7 allows you to override the object reflection for certain object-types. This can be useful for objects with dangerous properties or complex properties.

LogManager.Setup().SetupSerialization(s=>s.RegisterObjectTransformation<System.Net.WebException>(ex=>new{Type=ex.GetType().ToString(),Message=ex.Message,StackTrace=ex.StackTrace,Source=ex.Source,InnerException=ex.InnerException,Status=ex.Status,Response=ex.Response.ToString(),// Call your custom method to render stream as string}));

This can then be used together with:

${exception:format=ToString,Properties,Data}

Or like this for generating JSON:

${exception:format=@}