Do I need samples to apply for a patent? Is it okay to just have an idea and a design drawing?

Absolutely. Patents protect technical solutions, knowledge, and abstract products, not specific objects; as long as there is a technical solution that can be realized, you can apply for a patent. Physical objects and samples are not necessarily required. China’s patent system follows the first-to-file principle. For the same invention, the patent right is awarded to the person who applies first. If you are robbed of a patent application, there is no good solution unless you have evidence that you were the first to invent it, and then sue him for infringement of your patent application rights. Therefore, when applying for a patent, you must be aware of time and confidentiality.