Android : Why my project works on android but not on ios in codenameone?

I work on a big project with codenameone(i can't attach my codes because it's really big). I get android app and it's works on android devices. But recently i get ios build for this project and it's not working on ios device(just showing a white page instead of map). My project is a map-framework that render tiles and ... on graphics(i used graphics class for drawing, transforming, writing text and more). I used input stream for working with file because of File not supported. I need a solution to how debug and find my problem about ios build(why tiles doesn't showed). In fact i don'n know anything about ios and objective-c.

Thanks in advance.