iOS 屏幕比例适配

#import "ViewController.h"
#define  kScreenW  [UIScreen mainScreen].bounds.size.width
#define kScreenH  [UIScreen mainScreen].bounds.size.height
#define kScaleW   [UIScreen mainScreen].bounds.size.width  / 375
#define kScaleH    [UIScreen mainScreen].bounds.size.height / 667
@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
   [super viewDidLoad];
  //UI要求：  (50,60,275,40)
   UIView *scaleView = [[UIView alloc]initWithFrame:CGRectMake(50 *kScaleW, 60 *kScaleH, 275 * kScaleW, 40 *kScaleH)];
   scaleView.backgroundColor = [UIColor redColor];
   
   [self.view addSubview:scaleView];
   
   


   // Do any additional setup after loading the view, typically from a nib.
}