Here is a simple programs that creates two buttons programatically and sets its constraints.
#import "ViewController.h"@interface ViewController ()@property (nonatomic, strong) UIButton *myButton;@property (nonatomic, strong) UIButton *myButton2;@end@implementation ViewController- (void)viewDidLoad { [super viewDidLoad]; UIView *superview = self.view; /* Create myButton and add to our view*/ self.myButton = [UIButton buttonWithType:UIButtonTypeRoundedRect]; self.myButton.translatesAutoresizingMaskIntoConstraints = NO; [self.myButton setTitle:@"Test" forState:UIControlStateNormal]; [self.view addSubview:self.myButton]; /* Constraint to position myButton's X*/ NSLayoutConstraint *myButtonXConstraint = [NSLayoutConstraint constraintWithItem:self.myButton attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationGreaterThanOrEqual toItem:superview attribute: NSLayoutAttributeCenterX multiplier:1.0 constant:-60.0f]; /* Constraint to position myButton's Y*/ NSLayoutConstraint *myButtonYConstraint = [NSLayoutConstraint constraintWithItem:self.myButton attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:superview attribute: NSLayoutAttributeCenterY multiplier:1.0f constant:0.0f]; /* Add the constraints to button's superview*/ [superview addConstraints:@[ myButtonXConstraint, myButtonYConstraint]]; self.myButton.backgroundColor = [UIColor greenColor]; /* Create myButton2 and add to our view*/ self.myButton2 = [UIButton buttonWithType:UIButtonTypeRoundedRect]; self.myButton2.translatesAutoresizingMaskIntoConstraints = NO; [self.myButton2 setTitle:@"Test" forState:UIControlStateNormal]; [self.view addSubview:self.myButton2]; /* Constraint to position myButton2's X*/ NSLayoutConstraint *myButton2XConstraint = [NSLayoutConstraint constraintWithItem:self.myButton2 attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationGreaterThanOrEqual toItem:superview attribute: NSLayoutAttributeCenterX multiplier:1.0 constant:60.0f]; /* Constraint to position myButton2's Y*/ myButton2XConstraint.priority = UILayoutPriorityDefaultHigh; NSLayoutConstraint *centerYMyConstraint = [NSLayoutConstraint constraintWithItem:self.myButton2 attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationGreaterThanOrEqual toItem:superview attribute: NSLayoutAttributeCenterY multiplier:1.0f constant:0.0f]; [superview addConstraints:@[centerYMyConstraint, myButton2XConstraint]]; self.myButton.backgroundColor = [UIColor greenColor];} |