Can I have an optional parameter for an ASP.NET SOAP web service
Solution 1
You can have a Overloaded Method in webservices with MessageName attribute. This is a workaround to achieve the overloading functionality.
Look at http://msdn.microsoft.com/en-us/library/byxd99hx%28VS.71%29.aspx
[WebMethod(MessageName="Add3")]
public double Add(double dValueOne, double dValueTwo, double dValueThree)
{
return dValueOne + dValueTwo + dValueThree;
}
[WebMethod(MessageName="Add2")]
public int Add(double dValueOne, double dValueTwo)
{
return dValueOne + dValueTwo;
}
The methods will be made visible as Add2
and Add3
to the outside.
Solution 2
If you REALLY have to accomplish this, here's a sort of hack for the specific case of a web method that has only primitive types as parameters:
[WebMethod]
public void MyMethod(double requiredParam1, int requiredParam2)
{
// Grab an optional param from the request.
string optionalParam1 = this.Context.Request["optionalParam1"];
// Grab another optional param from the request, this time a double.
double optionalParam2;
double.TryParse(this.Context.Request["optionalParam2"], out optionalParam2);
...
}
Solution 3
I know this post is little old. But I think the method names should be same for the example from Rasik. If both method names are same, then where overloading comes there. I think it should be like this:
[WebMethod(MessageName="Add3")]
public double Add(double dValueOne, double dValueTwo, double dValueThree)
{
return dValueOne + dValueTwo + dValueThree;
}
[WebMethod(MessageName="Add2")]
public int Add(double dValueOne, double dValueTwo)
{
return dValueOne + dValueTwo;
}
Solution 4
In accordance with MinOccurs Attribute Binding Support and Default Attribute Binding Support:
-
Value type accompanied by a public bool field that uses the Specified naming convention described previously under Translating XSD to source - minOccurs value of output
<element>
element 0.
result:[WebMethod] public SomeResult SomeMethod(bool optionalParam, [XmlIgnore] bool optionalParamSpecified)
<s:element minOccurs="0" maxOccurs="1" name="optionalParam" type="s:boolean" />
-
Value type with a default value specified via a System.Component.DefaultValueAttribute - minOccurs value of output
<element>
element 0. In the<element>
element, the default value is also specified via the default XML attribute.
result:[WebMethod] public SomeResult SomeMethod([DefaultValue(true)] bool optionalParam)
<s:element minOccurs="0" maxOccurs="1" default="true" name="optionalParam" type="s:boolean" />
Solution 5
You can not have overloaded Web Service methods. The SOAP protocol does not support it. Rasik's code is the workaround.
hermgerm
Updated on July 27, 2021Comments
-
hermgerm almost 3 years
I want to build a webservice with this signature, which does not throw an exception if param2 is left empty. Is this possible?
[WebMethod] public string HelloWorld(string param1, bool param2) { }
The exception is a System.ArgumentException that is thrown when trying to convert the empty string to boolean.
Ideas that have not worked so far:
-
method overloading is not allowed for webservices, like
public string HelloWorld(string param1) { return HelloWorld(param1, false); }
as suggested here:
- make
bool
nullablebool?
. Same exception. - manipulate the WSDL, see this answer
My question is related to this question, but the only answer points to WCF contracts, which I have not used yet.
-