Programming VIP

Today, I'd like to introduce a linear layout artifact UIStackView launched by iOS9. If your project is at least suitable for iOS9, you can use it happily. In the AutoLayout layout, we need to set various dependencies for the subview. When we need to insert or delete a view, we need to change a lot of constraints in it. In terms of pure code, M ...

Several iOS attribute keywords 1.nonatomic,atomiac: Nonatomic: nonatomic, atomiac atomic. The default attribute is atomiac, that is, atomic. Nonatomic has high execution efficiency. atomiac: reading and writing is safe, but inefficient, not absolutely safe. 2.readwrite,readonly: Readwrite read-write, readonly read-only. The default property ...