Create and center a button using Autolayout

CreateAndCenterButtonWithAutoLayout

    self.insertTextButton = [UIButton buttonWithType:UIButtonTypeSystem];
    [self.insertTextButton setTitle:@"Press Me" forState:UIControlStateNormal];
    [self.insertTextButton sizeToFit];
    self.insertTextButton.translatesAutoresizingMaskIntoConstraints = NO;
    [self.insertTextButton addTarget:self action:@selector(insertText) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:self.insertTextButton];
    
    [self.view addConstraint: [NSLayoutConstraint constraintWithItem:self.insertTextButton
                                 attribute:NSLayoutAttributeCenterX
                                 relatedBy:NSLayoutRelationEqual
                                    toItem:self.view
                                 attribute:NSLayoutAttributeCenterX
                                multiplier:1.f constant:0.f]];
    
    [self.view addConstraint: [NSLayoutConstraint constraintWithItem:self.insertTextButton
                                 attribute:NSLayoutAttributeCenterY
                                 relatedBy:NSLayoutRelationEqual
                                    toItem:self.view
                                 attribute:NSLayoutAttributeCenterY
                                multiplier:1.f constant:0.f]];