Det beror på hur länge du är i Storbritannien.
To apply for a Schengen visa from the UK you must be a UK resident for at least three months. If this condition is not fulfilled, the Consulate of your country of preference will hardly take the application into consideration.
Non-residents such as travelers and tourists who plan on staying in the UK for 3 months or less should be discouraged from applying for a Schengen visa from within the UK. Instead, they should apply in their home country so that the application is processed, chances of getting a positive answer become greater.