How To Use Content Mode Of UI Controll IOS/Iphone

yourimageView.contentMode = UIViewContentModeCenter;
if ( yourimageView.bounds.size.width > yourimageView.size.width && 

yourimageView.bounds.size.height > yourimageView.size.height) {
   yourimageView.contentMode = UIViewContentModeScaleAspectFit;
}

typedef NS_ENUM(NSInteger, UIViewContentMode) {
UIViewContentModeScaleToFill,
UIViewContentModeScaleAspectFit,     
UIViewContentModeScaleAspectFill,    
UIViewContentModeRedraw,              

UIViewContentModeCenter,            
UIViewContentModeTop,
UIViewContentModeBottom,
UIViewContentModeLeft,
UIViewContentModeRight,
UIViewContentModeTopLeft,
UIViewContentModeTopRight,
UIViewContentModeBottomLeft,
UIViewContentModeBottomRight,
};