c# - Deserialize empty XML element as Guid.Empty -

i have troubles deserializing.

<order>     ...     <cardnumber />     ... </order> 

if use

<cardnumber>00000000-0000-0000-0000-000000000000</cardnumber> 

it's working normally, in case when use <cardnumber /> - object not deserializing (

is there way deserialize empty element guid.empty?

property should mapped value of element:

[xmlelement(elementname = "cardnumber")] [jsonproperty("cardnumber")] public guid? cardnumber { get; set; } 

same situation in json works , use guid.empty instead of empty element value

{     "cardnumber": "" } 

the exception seeing explains problem clearly:

system.invalidoperationexception occurred   message="there error in xml document (3, 3)."   innerexception: system.formatexception        message="guid should contain 32 digits 4 dashes (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)." 

as stated, xmlserializer not support deserializing empty string guid. need conversion manually using surrogate property:

[xmlroot("order")] public class order {     [xmlignore]     [jsonproperty("cardnumber")]     public guid? cardnumber { get; set; }      [xmlelement(elementname = "cardnumber", isnullable = true)]     [browsable(false), editorbrowsable(editorbrowsablestate.never), debuggerbrowsable(debuggerbrowsablestate.never)]     [jsonignore]     public string xmlcardnumber     {                 {             if (cardnumber == null)                 return null;             else if (cardnumber.value == guid.empty)                 return "";             return xmlconvert.tostring(cardnumber.value);         }         set         {             if (value == null)                 cardnumber = null;             else if (string.isnullorempty(value))                 cardnumber = guid.empty;             else                 cardnumber = xmlconvert.toguid(value);         }     } } 

if need in many different types have guid? properties, can extract surrogate type so:

[xmltype(anonymoustype = true, includeinschema = false)] public class xmlguid {     [xmlignore]     public guid guid { get; set; }      [xmltext]     public string xmlcardnumber     {                 {             if (guid == guid.empty)                 return null;             return xmlconvert.tostring(guid);         }         set         {             if (string.isnullorempty(value))                 guid = guid.empty;             else                 guid = xmlconvert.toguid(value);         }     }      public static implicit operator guid?(xmlguid x)     {         if (x == null)             return null;         return x.guid;      }      public static implicit operator xmlguid(guid? g)     {         if (g == null)             return null;         return new xmlguid { guid = g.value };     }      public static implicit operator guid(xmlguid x)     {         if (x == null)             return guid.empty;         return x.guid;      }      public static implicit operator xmlguid(guid g)     {         return new xmlguid { guid = g };     } } 

and use like:

[xmlroot("order")] public class order {     [xmlelement(type = typeof(xmlguid), elementname = "cardnumber", isnullable = true)]     [jsonproperty("cardnumber")]     public guid? cardnumber { get; set; } } 

here taking advantage of fact xmlelementattribute.type property automatically picks implicit conversion defined guid? , xmlguid.