What is a WCF OperationContract? I dont really understand what it does
WCF uses an opt-in model to define what belongs to one of its contracts. In a service contract interface, only methods decorated with [OperationContract] are exposed to the client. That means that, in the interface below, if used within a WCF service, a client could call both Add and Subtract operations, but not Multiply.
[ServiceContract]
public interface ICalculator
{
[OperationContract]
int Add(int x, int y);
[OperationContract]
int Subtract(int x, int y);
// Not decorated
int Multiply(int x, int y);
}
Every method you want to be able to the user calling from his client side must be declared like that.
Related
I'm trying to create a RESTful WCF service. I get a runtime error saying you can't have 2 of the same method names in your service class:
[OperationContract, WebGet]
...
string Get();
[OperationContract, WebGet]
...
string Get(int id);
Why in the world can't you! they are both different signatures. If I'm to get this to work like REST like I want, which is to be able to overload stuff like this, then that would suck and WCF is not for me.
Has anyone been able to have 2 of the same method names in your so-called attempt to make WCF restful?
you can override service method by using OperationContract name property with define separate routes.Your service interface should look like
[OperationContract(Name = "GetemployeeName")]
string Get(string param);
[OperationContract(Name = "GetemployeeAge")]
bool Get(long sysID);
In the project I am working on I need to call webservices (asmx).I would like to call them using wcf and using the channelfactory(No adding service Reference).
Some might have an interface(contract)many dont.
Is there an end to end example how to do it?
var service=ChannelFactory<?>... How do I get the webserviceContract.
Surely this must be a common scenario to be able to call a webservice (asmx)
Thanks for your time
To expand upon my comment, you should be able to create an interface that has methods that match the web service methods in the asmx service. For example:
Web Service Methods
string GetMessage()
void SendMessage(string message)
int AddNumbers(int x, int y)
Service Contract
[ServiceContract]
public interface IServiceName
{
[OperationContract]
string GetMessage();
[OperationContract]
void SendMessage(string message);
[OperationContract]
int AddNumbers(int x, int y)
}
ChannelFactory
ChannelFactory<IServiceName> serviceFactory =
new ChannelFactory<IServiceName>(new BasicHttpBinding(),
"http://www.services.com/Service.asmx");
Not 100% sure this will work, but it would be easy to try out. Also, you'd probably want to set the namespace on the service contract ([ServiceContract(Namespace = "somenamespace")]) to match the legacy asmx service, otherwise the messages might not get processed.
I want to know if we can override WCF methods or web service methods. If so, then how?
Try this for overloading WCF service methods
[ServiceContract]
public interface IMyCalculator
{
[OperationContract(Name="AddFloats")]
float Add(float operand1, float operand2);
[OperationContract(Name="AddIntegers")]
int Add(int operand1,int operand2);
}
Method overriding is not possible in WCF you can only implement the method overloading as explained in this posts.
Even I giving the code below for method overloading:
[ServiceContract]
public interface IMyCalculator
{
[OperationContract(Name="AddFloats")]
float Add(float operand1, float operand2);
[OperationContract(Name="AddIntegers")]
int Add(int operand1,int operand2);
}
For example, is this correct?
[OperationContract]
bool IsHappy(string userID);
bool IsSad(string userID);
bool IsHungry(string userID);
Is that a valid body of operations for a WCF ServiceContract or do I have to do it this way:
[OperationContract]
bool IsHappy(string userID);
[OperationContract]
bool IsSad(string userID);
[OperationContract]
bool IsHungry(string userID);
You must denote every method that you want to expose from the service with [OperationContract]. You are free to have methods without this attribute in your service class but those methods will not be exposed in the service metadata and will not be accessible to the client.
If all three methods are part of the service contract then all three must have an [OperationContract] attribute - your second example is correct.
I have a WCF webservice that has the following service contract
[ServiceContract(Namespace = "http://example.org")]
public interface IEquinoxWebservice
{
[OperationContract]
Guid Init();
[OperationContract]
List<Message> Dequeue(Guid instanceId);
[OperationContract]
void Enqueue(Guid instanceId, Message message);
[OperationContract]
void Dispose(string instanceId);
}
Message class is an abstract class that is implemented by a bunch of concrete message classes.
I want to make all the concrete message classes available in the client proxy that is generated. Not just the message class.
Is there any way to make them available as types in the webservice so the standard Visual Studio proxy generator will create them?
You need to specify those types. See Data Contract Known Types.