IOS Advanced 21st Day (0531)

0531-autolayout not only can do the screen adaptation can also do the system adaptation uidynamic do physical animation. The effect can be as follows:

AutoLayout

AutoLayout is an "automatic layout" technique designed to lay out UI interfaces. With AutoLayout, please forget frame

AutoLayout is stronger than autoresizing, both incompatible

2 Core concepts of AutoLayout

• Reference
• Constraints

Implementing AUTOLAYOUT-VFL with Code (Visual Format Language)

The following ideas are implemented:

Nslayoutconstraint's explanation:

Add a UIView to the parent control view and use the Nslayoutconstraint reference constraint to implement:

In order to simplify AutoLayout Apple launched the VFL language

VFL Example 1:

Operation Result:

Note: The inside metrics is used for positioning, just as[NSString StringWithFormat(@"%d", 10)]

As shown in the following:

VFL Example 2:

Operation Result:

Effects of AutoLayout on Uilabel, such as:

AutoLayout do animation

Note: layoutIfNeeded the method is used for AutoLayout animation. setNeedsDisplay is the quartz2d brush frames are redrawn DrawInrect: to draw things on the layer layers of the interface view.

IOS Advanced 21st Day (0531)