我发现的一个解决方案是重载addConstraint:方法并在添加约束之前对其进行修改:

The one solution I found is to overload the addConstraint: method and modify constraints before they'll be added:

- (void)addConstraint:(NSLayoutConstraint *)constraint
{
    if(constraint.firstItem == self || constraint.secondItem == self) {
        if(constraint.firstAttribute == NSLayoutAttributeLeading) {
            constraint.constant += self.leftBorderWidth;
        } else if (constraint.firstAttribute == NSLayoutAttributeTrailing) {
            constraint.constant += self.rightBorderWidth;
        } else if (constraint.firstAttribute == NSLayoutAttributeTop) {
            constraint.constant += self.topBorderWidth;
        } else if (constraint.firstAttribute == NSLayoutAttributeBottom) {
            constraint.constant += self.bottomBorderWidth;
        }
    }

    [super addConstraint:constraint];
}

然后还要在xxxBorderWidth设置器中处理此约束.

And then also handle this constraints in xxxBorderWidth setters.