I’m using C# and I have windows form and web service…
I have a custom object that I want to send to the web service..
sometime, the object may contain a huge of data..
as a best performance, what is the best way to send a custom object to the web service?
Web Services are designed to handle custom objects as long as they eventually breakdown into some standard types. As per sending a huge data, there are MTOM and older DIME. If it’s within LAN and against other .NET client, you might want to look into non-Web Services ways like Remoting or plain http.
See How to: Enable a Web Service to Send and Receive Large Amounts of Data.