how do I make 1st app listen from 2nd app?

example i want to make an app have listbox, and an custom dll which i can use on second app.

the first app is running always and listening for the second a开发者_运维问答pp, as soon as the dll function return value on second app , it will return value to the 1st app and insert the value to the lisbox.

does any one have any example how can i do it ? and what is this process called in c# ?

Thanks

This is called Inter-Process Communication.

Interprocess communication for Windows in C# (.NET 2.0)

You can also use a socket using the loopback ip address 127.0.0.1 which is easier to understand than IPC, but not reccomended for security reasons.

There are two technologies that I know of for the .NET framework. But they all boil down into inter-process communication. One is .NET Remoting and the other is Windows Communication Foundation. Depending on the version of the .NET framework you are using and the type of application I'd recommend using WCF.