如何从UIViewController访问drawrect方法？ [英] How to access drawrect method from UIViewController?

问题描述

我正在使用Xcode 4.2，并且有一个UIViewController代表场景之一。

I am using Xcode 4.2 and have a UIViewController representing one of the scenes.

在其中，我有 viewWillAppear

[NSTimer scheduledTimerWithTimeInterval: FramesPerSecond target:self 
selector:@selector(gameLoop) userInfo:nil repeats:YES];

在 gameLoop 方法内部，我有

[[self view] setNeedsDisplay];

问题：

drawRect 方法未调用（据我了解，应从 setNeedsDisplay

drawRect method is not being called (As i understand it it should be called from setNeedsDisplay

问题：

• 是否可以定义<$ c UIViewController 类中的$ c> drawRect 方法，因此应该如何声明它？在 UIView上调用它据我了解。


• 如果不可能，您将如何使用Xcode 4.2解决这种情况？

• Is it possible to define drawRect method inside a UIViewController class and is so how should one declare it? It is called on a UIView as i understand it.
• If is it not possible, how would you address the situation using Xcode 4.2?

推荐答案

否。您需要将UIViewController控制的UIView子类化。

No. You would need to subclass the UIView that the UIViewController controls.

（作为一个附带说明，计时器并不是游戏循环的好选择，因为您无法获得完全可预测的计时。）

(As a side note, timers aren't great for game loops because you don't get totally predictable timing.)

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