如何在Objective C中使用从iOS 9创建的约束？在Swift中,这应该是这样的:
button.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true button.heightAnchor.constraint(equalToConstant: 100).isActive = true
constraints objective-c ios nslayoutconstraint swift
constraints ×1
ios ×1
nslayoutconstraint ×1
objective-c ×1
swift ×1