iPhone各种尺寸

iPhone 6 Plus      736x414 points      2208x1242 pixels     3x scale     1920x1080 physical pixels     401 physical ppi      5.5"

iPhone 6             667x375 points     1334x750 pixels       2x scale      1334x750 physical pixels      326 physical ppi　　 4.7"

iPhone 5             568x320 points     1136x640 pixels       2x scale      1136x640 physical pixels      326 physical ppi　　 4.0"

iPhone 4             480x320 points     960x640 pixels         2x scale       960x640 physical pixels　　 326 physical ppi　　 3.5"

iPhone 3GS         480x320 points     480x320 pixels        1x scale       480x320 physical pixels 　　 163 physical ppi　　 3.5”

@property (nonatomic, weak) UIActivityIndicatorView *loadingView;