iOS-动态修改xib中控件的大小

#import ViewController.h
 
@interface ViewController ()
@property (strong, nonatomic) IBOutlet NSLayoutConstraint *top;
@property (strong, nonatomic) IBOutlet NSLayoutConstraint *height;
 
@end
 
@implementation ViewController
 
- (void)viewDidLoad {
    [super viewDidLoad];
    
    
    self.top.constant+=100;
    self.height.constant+=100;
    
}
 
@end