Instantiating CAO without using new operator

[Abhishek Srivastava]

Hello All,

I want my clients to use my remoted object by means of interfaces. These
interfaces also ensure clean seperation between client and server.

The approach I know to instantiate a CAO is

RemotingConfiguration.RegisterActivatedClientType(
typeof(MyObject),
"tcp://localhost:1234/MyServer");
MyObject obj = new MyObject();

But I cannot do this because I am using an Interface for the client to
invoke the method on the server.

How to have an interface based client server coupling when using CAOs?

Thanks for your help in advance.

regards,
Abhishek.

 

[Guest]

Hi Abhishek,

Check out the Activator.CreateInstance method. This method can be used to create the instance of CAO using interface.

Take a look at the following links,

<http://msdn.microsoft.com/library/d...rfsystemactivatorclasscreateinstancetopic.asp>

<http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndotnet/html/introremoting.asp>

Hope this helps...

 

[Abhishek Srivastava]

I have already tried Activator.CreateInstance method. But it does not work.

The error message that will appear is

Unhandled Exception: System.MemberAccessException: Cannot create an
instance of an interface.
at System.RuntimeType.CreateInstanceImpl(Boolean publicOnly)
at System.Activator.CreateInstance(Type type, Boolean nonPublic)
at Client.Main(String[] args)

I am not providing the implementation of the remote object to the
client. The client binds only to the interface being implemented by the
remote object.

I found a solution which involves using soapsuds. However it works only
for the http channel whereas I want to use tcp channel.

regards,
Abhishek.

 

[Sunny]

Hi,
can you post your CreateInstance line?

Also, you do not have to call RegisterActivatedClientType before that.

Sunny

I have already tried Activator.CreateInstance method. But it does not work.

The error message that will appear is

Unhandled Exception: System.MemberAccessException: Cannot create an
instance of an interface.
at System.RuntimeType.CreateInstanceImpl(Boolean publicOnly)
at System.Activator.CreateInstance(Type type, Boolean nonPublic)
at Client.Main(String[] args)

I am not providing the implementation of the remote object to the
client. The client binds only to the interface being implemented by the
remote object.

I found a solution which involves using soapsuds. However it works only
for the http channel whereas I want to use tcp channel.

regards,
Abhishek.

Hi Abhishek,

Check out the Activator.CreateInstance method. This method can be used to create the instance of CAO using interface.

Take a look at the following links,

<http://msdn.microsoft.com/library/d...rfsystemactivatorclasscreateinstancetopic.asp>

<http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndotnet/html/introremoting.asp>

Hope this helps...

 

[Nicholas Paldino [.NET/C# MVP]]

Abhishek,

You should call the version of CreateInstance which takes an array of
objects to use as activation attributes. The attribute that you will want
to pass is an instance of UrlAttribute, which specifies where the object
will be activated. Then, you have to unwrap the ObjectHandle that is
returned, and then cast that to the interface.

There is an example in the documentation for CreateInstance.

Hope this helps.

--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

I have already tried Activator.CreateInstance method. But it does not work.

The error message that will appear is

Unhandled Exception: System.MemberAccessException: Cannot create an
instance of an interface.
at System.RuntimeType.CreateInstanceImpl(Boolean publicOnly)
at System.Activator.CreateInstance(Type type, Boolean nonPublic)
at Client.Main(String[] args)

I am not providing the implementation of the remote object to the
client. The client binds only to the interface being implemented by the
remote object.

I found a solution which involves using soapsuds. However it works only
for the http channel whereas I want to use tcp channel.

regards,
Abhishek.

Hi Abhishek,

Check out the Activator.CreateInstance method. This method can be used to create the instance of CAO using interface.

Take a look at the following links,

<http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html
/frlrfsystemactivatorclasscreateinstancetopic.asp><http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndotnet/h
tml/introremoting.asp>

Hope this helps...

 

[Allen Anderson]

there are many ways to do this. Check out my article here on a better
way of creating your CAO.

http://www.glacialcomponents.com/ArticleDetail.aspx?articleID=CAOGuide

Allen Anderson
http://www.glacialcomponents.com
mailto: allen@put my website url here.com