IOS 雜筆－8（loadView、viewDidLoad、viewWillAppear、viewDidAppear等簡介），loadviewviewdidload

IOS 雜筆－8（loadView、viewDidLoad、viewWillAppear、viewDidAppear等簡介），loadviewviewdidload

loadView; 
This is where subclasses should create their custom view hierarchy if they aren't using a nib. Should never be called directly.
這是當他們沒有正在使用nib視圖頁面，子類將會建立自己的自訂視圖層。絕不能直接調用。

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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.
在視圖載入後被調用，如果是在代碼中建立的視圖載入器，他將會在loadView方法後被調用，如果是從nib視圖頁面輸出，他將會在視圖設定好後後被調用。

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 viewWillAppear: 

Called when the view is about to made visible. Default does nothing
視圖即將可見時調用。預設情況下不執行任何操作

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viewDidAppear: 
Called when the view has been fully transitioned onto the screen. Default does nothing
視圖已完全過渡到螢幕上時調用

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viewWillDisappear:
Called when the view is dismissed, covered or otherwise hidden. Default does nothing
視圖被駁回時調用，覆蓋或以其他方式隱藏。預設情況下不執行任何操作

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viewDidDisappear:
Called after the view was dismissed, covered or otherwise hidden. Default does nothing
視圖被駁回後調用，覆蓋或以其他方式隱藏。預設情況下不執行任何操作