How to back up and restore the localDb 2012 database?

I am trying to backup my localDB file using the method file.Copy()

, but it produces the following IOException

:

The process cannot access the file '. \ DB.mdf' because it is in use by another process.

And when I try to make a backup with the following script:

@"BACKUP DATABASE " + DatabaseName + " TO DISK = N'" + BackUpLocation + @"\" + BackUpFileName + @"'"  

      

        
        
        
      

    

it outputs the following SqlException

:

The database "DB" does not exist. Make sure the name is entered correctly.

My connection string:

Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\DB.mdf;Integrated Security=True;Connect Timeout=30

      

        
        
        
      

    

What is the best way to make a backup in this situation?