Overloading routines in WebServices

Web services are also classes just like any other .NET classes. Since a web service is a class it can utilise all the OO features like method overloading. However to use this feature with WebMethods we need toadd a little extra syntax.

Creating WebMethods
Create a WebService that has the following overloaded methods:

public string GetGreeting()
public string GetGreeting(string p_Name)
public string GetGreeting(string p_Name, string p_Message)

All these three methods return variants of a Greeting message. Now mark the methods as Web Methods, simply add the [WebMethod] attribute.

[WebMethod]
public string GetGreeting()
{
return “Hi Guest”;
}

[WebMethod]
public string GetGreeting(string p_Name)
{
return “Hi ” + p_Name + “!”;
}

[WebMethod]
public string GetGreeting(string p_Name, string p_Message)
{
return “Hi ” + p_Name + “!” + p_Message;
}

Run the WebService in the browser. That should give an error saying that the GetGreeting() methods use the same message name ‘GetGreeting’.

Adding the MessageName property.
Add the MessageName property to the WebMethod attribute as shown below:

[WebMethod]public string GetGreeting()
{
return “Hi Guest”;
}
[WebMethod (MessageName="WithOneString")]
public string GetGreeting(string p_Name)
{
return “Hi ” + p_Name + “!”;
}
[WebMethod (MessageName="WithTwoStrings")]
public string GetGreeting(string p_Name, string p_Message)
{
return “Hi ” + p_Name + “!” + p_Message;
}

Now compile the WebService and run in the browser. You can see that the first method is displayed as GetGreeting but for the second and third method the alias we set using the MessageName property is displayed.

You could of course use the alias’ as your method names – but that’d be taking the fun out of OO

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Possibly related posts: (automatically generated)

• Overloading in Web Methods