[We all love Paul Hegarty] Stanford IOS8 open class personal notes 41 Animation animation_html/css_WEB-ITnose

There are the following types of animations in IOS:

The first one is to add animation to the elements of UIView.
The second is the animation of the controller, such as the usage of the navigation controller introduced before.
The third one is Core Animation, which is a very powerful framework, but is beyond the scope of this course.
The fourth type is Dynamic Animation, which is based on the physical characteristics of the device, such as shaking the phone, changing direction, etc.
This article will explain the first situation:

Animation effects can be achieved using attributes such as frame, transform, and alpha.
You can call methods of UIView to set animations. There are closures in the parameters of these methods that can help us set the above properties of UIView. The code in the closure is executed immediately when the method is called. Some methods also have parameters named Closure of completion. In this closure, you can set the operation after the Animation is completed. For example, the following method declaration:

The usage is as follows:

The transparency of myView was originally 1. Now we call the method animateWithDuration. The only operation performed in animations is to set myView to be fully transparent. . The meaning of the first parameter 3.0 is that this transparent process will be completed within 3 seconds, and the meaning of the second parameter 2.0 is that the animation will be delayed by 2S. The third parameter options will be used in all animation methods. It is an enumeration indicating different animation types, which will be discussed later.
Animations are the operations we need to perform. Completion is the operation after completion. I just saw in the definition that the completion closure has a Boolean parameter, so $0 is used directly instead to indicate that the previous code has been executed. In this closure, Delete myView from the parent view collection to achieve true deletion.
In addition to using animateWithDuration to modify the attributes of the view, if you want to implement animations such as flipping, it cannot be achieved by relying on the three attributes above. At this time, there are special methods to choose from:

Usage example:

If you need to change the level of View, use the following method:

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