AutoLayoutでViewを上下中央配置にする。
(※ self.view:親 self.fooview:子)
// AutoLayoutの自動変換をOFF
[self.fooview setTranslatesAutoresizingMaskIntoConstraints:NO];
// X方向の制約
NSLayoutConstraint *xConstraint =
[NSLayoutConstraint constraintWithItem:self.fooview
attribute:NSLayoutAttributeCenterX
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeCenterX
multiplier:1.0
constant:0];
// Y方向の制約
NSLayoutConstraint *yConstraint =
[NSLayoutConstraint constraintWithItem:self.fooview
attribute:NSLayoutAttributeCenterY
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeCenterY
multiplier:1.0
constant:0];
[self.view addConstraint:xConstraint];
[self.view addConstraint:yConstraint];