Copying .mdf and ldf files without stoping sqlserver service

Question

Please can anyone tell me about how to backup the complete database without stopping the sqlserver window service..
i want to copy the .mdf and .ldf files in c# when sqlserver is running..
i am able to copy the files by stoping the sqlserver service.
 
Is it possible to copy the files(.mdf and .ldf) without stopping the sqlserver service in c#..
Please answer if anyone knows..!!