How to pass optional parameters for web method?

Question

I have a web method with multiple parameters. The web method is only dependent on 2 fields, the rest are all optional.

 [OperationContract]
 public string WarehouseContactInformation(int WAID (Required), string CN (Required), string CT (Optional), string CC (Optional), string CFN (Optional), string CD (Optional), string CE (Optional),string CW (Optional))

How to I declare these parameters as optional so that when I call the Web Method I only have to pass through the fields that i have values for, example:

WarehouseContactInformation(1,'Bill','00012311')
WarehouseContactInformation(1,'Bill','00012311','12415415','123525')

• शेखर: possible duplicate stackoverflow.com/questions/1723052/…

Answer 1

You can't. Web methods doesn't support optional parameters. When you generate proxy for web method, you make get the specific signature, according to which you client and server would exchange the messages. But it can't pass the optional parameters. You can use default parameters on the server side, but no optional.

• Jacques Bronkhorst: Do you have an example of these default params that I can use server Side?
• Alex: Well, it like a standart default parameters in your classes: public string WarehouseContactInformation(int WAID, string CN , string CT = "defaultValue"). After this you proxi method will be generated as WarehouseContactInformation(int WAID, string CN) and each time you call it - it would call WarehouseContactInformation(int WAID, string CN , string CT = "defaultValue") on your service.
• Jacques Bronkhorst: Thanks. You sir are a gentlemen And A scholar!
• Mogli: @voo Sir please check my answer posted below, am i doing wrong, if i doing this.Guide me.Thanks

Answer 2

What i did is: send the parameter binded with XML, and don't bind the values of optional parameters leave that blank.

 XmlDocument xmlDoc = new XmlDocument();
 xmlDoc.LoadXml(
 "<registration>" +
 "<field1>" + value + "</field1>" +
 "<field2>" + value(or leave blank) + "</field2>" +
 "<field3>" + value + "</field3>" +
 "<field4>" + value + "</field4>" +
 "</registration>");
 int status = objectOfService.methodName(xmlDoc);

and in web service you can do like

 public int UpdateUser(XmlNode node)
 {
 String filed1Value=node["field1"].InnerText;
 }

Hope it helps.

• Alex: Yes, you can pass your parameters in XML, or JSon or even object, and this is a way to avoid optional parameters in this case. But symanticly it is more correct pass a part of data using methods to make the code more obvious. For example when I see the second part of your code, I don't understand what is the XmlNode. But if I change it to UpdateUser(string login, string pass, string role) - it becomes a bit clear and avoided of Xml parsing and unparsing