Basically Implementation#01 and Implementation#02 should be same. But Implementation sometimes gets exception if modifiers = ModifierKeys.None.
//Implementation # 01:
KeyBinding k = new KeyBinding(command, key, modifiers);
//Implementation # 02:
KeyBinding keyBinding = new KeyBinding();
keyBinding.Command = command;
keyBinding.Key = key;
keyBinding.Modifiers = modifiers;
So, use the 2nd way of implementation if required.