How can I save the class in dll

How can I save the class in dll

You need first to compile your class following what Antenka mentioned. The dll will be created at the bin\Debug subdirectory if you're compiling it using Visual Studio.

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.