`Double.ToString` with N number of decimal places [duplicate]

I know that if we want to display a double as a two decimal digit, one would just have to use

public void DisplayTwoDecimal(double dbValue)
{
  Console.WriteLine(dbValue.ToString("0.00"));
}

But how to extend this to N decimal places, where N is determined by the user?

 public void DisplayNDecimal(double dbValue, int nDecimal)
    {
     // how to display
    }

Use "Nx" for x decimal digits.

 public void DisplayNDecimal(double dbValue, int nDecimal)
 {
   Console.WriteLine(dbValue.ToString("N" + nDecimal));
 }