ios - UIViewController didRotateFromInterfaceOrientation : not being called

Question

我正在编写一个 iOS 游戏应用程序，其中有一些 View 在屏幕上飞来飞去，应该可以在横向和纵向模式下播放。对于旧设备，出于性能原因，我决定在界面旋转时停止动画。应按照苹果文档中的描述停止和继续动画 https://developer.apple.com/library/mac/documentation/cocoa/conceptual/coreanimation_guide/AdvancedAnimationTricks/AdvancedAnimationTricks.html效果很好。所以我决定在 willRotateToInterfaceOrientation: (UIInterfaceOrientation) toInterfaceOrientation duration: (NSTimeInterval) duration 中暂停动画，并在 didRotateFromInterfaceOrientation: (UIInterfaceOrientation) fromInterfaceOrientation 中恢复动画。问题是，如果我将 View 的图层速度设置为零，则永远不会调用 didRotateFromInterfaceOrientation: (UIInterfaceOrientation) fromInterfaceOrientation。有人对这种奇怪的行为有解释吗？

我在做的细节是:

SGMathsMasterNoteView *noteView = [SGMathsMasterNoteView noteViewWithExercise: self.nextExercise andDelegate: self];
[self.animationContainer insertSubview: noteView aboveSubview: self.noteStackView];
[noteView startAnimation];

SGMathsMasterNoteView.m

- (void) startAnimation {
    self.frame = self.noteAnimationView.noteStackView.frame;
    CAAnimation *ani = self.noteAnimationView.motionAnimation;
    [self.layer addAnimation: ani forKey: @"fly"];
    self.layer.speed = 1.0;
    self.center = self.noteAnimationView.destroyPoint;
}

- (void) pauseAnimation {
    self.layer.speed = 0.0;
    self.layer.timeOffset = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
}

- (void) resumeAnimation {
   CFTimeInterval pausedTime = self.layer.timeOffset;
   self.layer.speed = 1.0;
   self.layer.timeOffset = 0.0;
   self.layer.beginTime = 0.0;
   CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
   self.layer.beginTime = timeSincePause;
}

SGGameViewController.m

- (void) willRotateToInterfaceOrientation: (UIInterfaceOrientation) toInterfaceOrientation duration: (NSTimeInterval) duration {
   for (SGMathsMasterNoteView *noteView in [self.animationContainer.subviews allObjectsOfClass: [SGMathsMasterNoteView class]]) {
      [noteView pauseAnimation];
   }
}

- (void) didRotateFromInterfaceOrientation: (UIInterfaceOrientation) fromInterfaceOrientation {
   for (SGMathsMasterNoteView *noteView in [self.animationContainer.subviews allObjectsOfClass: [SGMathsMasterNoteView class]]) {
      [noteView resumeAnimation];
   }
}

Answer 1

乍一看，您的 willRotateToInterfaceOrientation:duration: 和 didRotateFromInterfaceOrientation: 方法不会调用必需的 super。我的猜测是，由于 super 在旋转之前未被调用，因此它阻止了旋转后方法的调用。

来自 UIViewController 类引用:

Your implementation of this method must call super at some point during its execution.

这是您的实现的更正版本:

- (void) willRotateToInterfaceOrientation: (UIInterfaceOrientation) toInterfaceOrientation duration: (NSTimeInterval) duration
{
    [super willRotateToInterfaceOrientation: toInterfaceOrientation duration: duration];

    for (SGMathsMasterNoteView *noteView in [self.animationContainer.subviews allObjectsOfClass: [SGMathsMasterNoteView class]])
    {
        [noteView pauseAnimation];
    }
}

- (void) didRotateFromInterfaceOrientation: (UIInterfaceOrientation) fromInterfaceOrientation
{
    [super didRotateFromInterfaceOrientation: fromInterfaceOrientation];

    for (SGMathsMasterNoteView *noteView in [self.animationContainer.subviews allObjectsOfClass: [SGMathsMasterNoteView class]])
    {
        [noteView resumeAnimation];
    }
}

我先调用了 super，但尝试在最后调用它。

希望这能解决您的问题。