使用自动布局约束设置两个uibutton之间的垂直距离

Question

我希望ButtonA保持原状，ButtonB将距离x垂直向下移动远离它。

Answer 1

// Using Autolayout.

UIButton *buttonA, *buttonB;
UIView *fatherView; // The superview of buttonA and B.( The view where they are inside).
CGFloat distance;
NSLayoutConstraint *constraint = [NSLayoutConstraint constraintWithItem:buttonB attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:buttonA attribute:NSLayoutAttributeBottom multiplier:1 constant:distance];

[fatherView addConstraint:constraint];

// Without autolayout, maybe more easy.
buttonB.center = CGPointMake(buttonA.center.x, buttonA.center.y + distance);