iOS开发:视图生命周期

 

iOS应用的视图状态分为以下几种

  • 在viewcontroller的父类UIViewController中可以看到如下代码,通过重写不同的方法对操作视图渲染。
@available(iOS 2.0, *)
public class UIViewController{
 
   public func viewDidLoad() // Called after the view has been loaded. For view controllers created in code, this is after -loadView. For view controllers unarchived from a nib, this is after the view is set.
   public func viewWillAppear(animated: Bool) // Called when the view is about to made visible. Default does nothing
    public func viewDidAppear(animated: Bool) // Called when the view has been fully transitioned onto the screen. Default does nothing
    public func viewWillDisappear(animated: Bool) // Called when the view is dismissed, covered or otherwise hidden. Default does nothing
    public func viewDidDisappear(animated: Bool) // Called after the view was dismissed, covered or otherwise hidden. Default does nothing
public func didReceiveMemoryWarning() // Called when the parent application receives a memory warning. On iOS 6.0 it will no longer clear the view by default.
 
}
    • viewDidLoad():视图被加载到内存中时调用viewDidLoad方法,在该方法中可对视图上布局进行调整
    • viewWillAppear():视图可见前
    • viewDidAppear():视图已经可见,页面渲染完成后可以加载一些控件动画
    • viewWillDisappear():视图失去焦点前
    • viewWillDidDisappear():视图失去焦点后
    • didReceiveMemoryWarning():在iOS 6之后可使用此方法释放内存,包括视图控制器中的一些成员变量

 

posted @ 2015-11-12 16:14  Tonge  阅读(929)  评论(0编辑  收藏  举报