XML＆WCF POST请求：读取某些参数，其他则不读取

Question

I have a wcf restful service on a IIS server.

I have made some API, which can be called sending both xml or json.

I've made my C# classes and then, I'm testing it. With JSON is perfect, but I have still some issues with XML request.

I want to send the xml with a post and this is the xml I send:

 
 
 
 
  
  
  <?xml version="1.0" encoding="utf-8" ?> <SetClientiXML xmlns="http://tempuri.org/"> <dati> <ArrayOfWrapClienti xmlns="http://schemas.datacontract.org/2004/07/MultipayOnline" xmlns:i="http://www.w3.org/2001/XMLSchema-instance"> <WrapClienti> <CODRETE>0018</CODRETE> <CODICE>20685</CODICE> <NOME>ATER Azienda Territoriale</NOME> <INDIRIZZO>PIAZZA POZZA</INDIRIZZO> <CITTA>Verona</CITTA> <CAP>37123</CAP> <PROV>VR</PROV> <CODICEFISCALE>00223640236</CODICEFISCALE> <PIVA>223640236</PIVA> <EMAIL/> <ESPOSIZ_CONTABILE>937,02</ESPOSIZ_CONTABILE> <STATO>FALSE</STATO> </WrapClienti> </ArrayOfWrapClienti> </dati> <retista>3303903</retista> <hashedString>oklkokokokok</hashedString> </SetClientiXML>
 
 
  

the wcf read well "retista" and "hashedString", but "dati" is empty (0 elements), while I expect it has got the "wrapClienti" object I sent. This is the prototype of my API:

    [OperationContract]
    [WebInvoke(UriTemplate = "SetClienti.xml", Method = "POST", BodyStyle=WebMessageBodyStyle.Wrapped, RequestFormat = WebMessageFormat.Xml)]
    GenericResponse SetClientiXML(List<WrapClienti> dati, string retista, string hashedString);

So, the problem is that the List is empty.. why? How can I write the xml to make readable the list? Ask me if I can give to you more details.

UPDATE: More weird!!

With this xml:

<?xml version="1.0" encoding="utf-8" ?><SetClientiXML xmlns="http://tempuri.org/">
    <dati>
        <WrapClienti xmlns="http://schemas.datacontract.org/2004/07/MultipayOnline" xmlns:i="http://www.w3.org/2001/XMLSchema-instance"> 
            <CODRETE>0018</CODRETE> 
            <CODICE>20685</CODICE> 
            <NOME>A.T.E.R. Azienda Territoriale</NOME> 
            <INDIRIZZO>PIAZZA POZZA</INDIRIZZO> 
            <CITTA>Verona</CITTA> 
            <CAP>37123</CAP>
            <PROV>VR</PROV> 
            <CODICEFISCALE>00223640236</CODICEFISCALE> 
            <PIVA>223640236</PIVA> 
            <EMAIL/> 
            <ESPOSIZ_CONTABILE>937,02</ESPOSIZ_CONTABILE> 
            <STATO>FALSE</STATO> 
        </WrapClienti> 
    </dati>
    <retista>3303903</retista>
    <hashedString>oklkokokokok</hashedString>
</SetClientiXML>

the wcf read some attributes of the List, and other.. are nul!!!

I my WrapClienti I have a lof of attributes. Two of them are:

    private string p_CAP { get; set; }
    public string CAP
    {
        get
        {
            if (model == null)
                return p_CAP.ToSafeString();
            else
                return this.model.CAP.ToSafeString();
        }
        set { p_CAP = value; }
    }
    private string p_PROV { get; set; }
    public string PROV
    {
        get
        {
            if (model == null)
                return p_PROV.ToSafeString();
            else
                return this.model.PROV.ToSafeString();
        }
        set { p_PROV = value; }
    }

the problem is, with the xml above and with two breakpoint on the two set methods, only the set of PROV is called and, the one of CAP, not!!! Why? Now I'm really getting crazy... why this behavior??

Solution here .

Answer 1

This has to do with the ordering of the fields in your XML. It sounds very strange, but WCF DataContractSerializer is really fussy about the order in which the fields are encountered in the XML, but even worse, also in comparison to how they are defined in the code .

You see, the serializer wants the fields to be defined in alphabetical order, and if you serialize an instance of your class, you will find that the resulting XML fields are in alphabetical order. However, on deserialization, the serializer finds that the type you want to deserialize to has the fields defined in the "wrong" order. In this situation the behavior can seem random, but I think it has something to do with the fact that CAP should be the first field encountered, whereas PROV should be the last field, alphabetically.

So you have two options:

1. Reorder your XML and the fields in your class to be in alphabetical order, or

2. Decorate your class members with the DataMemeber property, and define the order of serialization.

You can do 2 like this:

[DataContract]
public class WrapClienti
{ 
    [DataMember(Order=1)]
    public string CAP { get; set; } 

    [DataMember(Order=2)]
    public string PROV { get; set; } 

    ...etc
}