UIView動畫塊會暫停動畫和完成代碼

我有一個動畫塊來執行簡單的基於變換的動畫，完成時從其超級視圖中刪除有問題的視圖。UIView動畫塊會暫停動畫和完成代碼

UIView *msgView = [[UIView alloc] initWithFrame:CGRectMake(160, 120, 160, 100)]; 

// Do stuff to set up the subviews of msgView. 

// Add the msgView to the superview (ViewController) that is going to display it. 

CATransform3D transform = CATransform3DMakeScale(2.5, 2.5, 1.0); 

[UIView animateWithDuration:5.0 
       animations:^(void){msgView.layer.transform = transform;} 
       completion:^(BOOL finished){[msgView removeFromSuperview];}];

我然後使用代碼作爲由Tech Q &甲1673 http://developer.apple.com/library/ios/#qa/qa1673/_index.html 詳述暫停動畫。

-(void)pauseLayer:(CALayer*)layer 
{ 
    CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil]; 
    layer.speed = 0.0; 
    layer.timeOffset = pausedTime; 
} 

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

但是，這段代碼並不妨礙完成代碼的執行。因此，爲了防止執行我更改代碼完成此代碼：

completion:^(BOOL finished){if(finished == TRUE)[msgView removeFromSuperview];};

雖然檢查結束== TRUE阻止而動畫塊暫停正在執行的完成代碼。如果在「取消暫停」動畫之前，持續時間現在已過時，則完成代碼將不會執行。即在這種情況下，msgView保留在超級視圖中。

無論如何暫停/取消暫停與完成代碼相關的動畫和定時器（如果這是怎麼回事）？

來源

2013-02-27 VariableSquid

有趣的問題。可以被解釋爲iOS中的錯誤。爲了解決這個問題，我建議你擺脫動畫的完成片段，而改爲創建自己的NSTimer，並將其當前的完成作爲其調用。通過這種方式，您可以在暫停圖層中停止定時器（通過將fireDate設置在將來）。裏面resumeLayer你重置fireDate是（timeSincePause + 5.0） – Rikkles 2013-02-28 10:26:09

我希望能夠直接獲得與完成代碼相關的CAMediaTiming，就像我們用層做的一樣。我認爲這將是一個更好的解決方案。 – VariableSquid 2013-02-28 11:32:18

我在iOS 6.1下編寫了一個測試應用程序，它的行爲正確，即轉換的計時器暫停。你在什麼操作系統下測試？ – Rikkles 2013-02-28 12:54:43

正如我在上面的評論中所說，似乎沒有問題。以下是在iOS 5.1和6.1中測試的。

用UIImageView *transView和UIButton *trigger創建故事板。下面是類：

TSTViewController.h：

@property (weak, nonatomic) IBOutlet UIImageView *transView; 
@property (weak, nonatomic) IBOutlet UIButton *trigger; 
@property (nonatomic) NSUInteger bState; 

- (IBAction)didPressTrigger:(id)sender;

TSTViewController.m：

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    self.bState = 0; // 0 is initial state 
         // 1 is transform being animated 
         // 2 is transform paused 
         // 3 is transform ended 
} 

- (IBAction)didPressTrigger:(id)sender { 
    switch (self.bState) { 
     case 0: 
     { 
      CATransform3D transform = CATransform3DMakeScale(2.5, 2.5, 1.0); 
      self.bState++; 
      [UIView animateWithDuration:5.0 
          animations:^(void){self.transView.layer.transform = transform;} 
          completion:^(BOOL finished){ 
           self.bState = 3; 
           NSLog(@"Done"); 
          }]; 
      break; 
     } 
     case 1: 
     { 
      self.bState++; 
      [self pauseLayer:self.transView.layer]; 
      break; 
     } 
     case 2: 
     { 
      self.bState = 1; 
      [self resumeLayer:self.transView.layer]; 
      break; 
     } 
     case 3: 
     { 
      [UIView animateWithDuration:0 animations:^(void){self.transView.layer.transform = CATransform3DIdentity;} 
          completion:^(BOOL finished) { 
           self.bState = 0; 
           NSLog(@"Reset"); 
          }]; 
      break; 
     } 
     default: 
      break; 
    } 
} 

-(void)pauseLayer:(CALayer*)layer 
{ 
    CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil]; 
    layer.speed = 0.0; 
    layer.timeOffset = pausedTime; 
} 

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

當您按下觸發按鈕，動畫開始。再按一次，動畫停止。等待10秒鐘，然後再次按下按鈕。動畫繼續並完成，並記錄「完成」。

來源

2013-03-01 06:58:12 Rikkles

UIView動畫塊會暫停動畫和完成代碼

回答

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