我有一组嵌套的UIView动画(在给定时间深2或3级),我希望能够暂停和恢复.其中一些动画使用-animateWithDuration：animations：completion：而其他动画使用-animateWithDuration：delay：options：animations：completion：以延迟动画块的执行.
我阅读并实现了Technical Q&A QA1673关于暂停层树中的所有动画,但我遇到了使用延迟参数的动画的问题.我可以暂停和恢复动画,但是当动画恢复时,任何与其相关的延迟的动画块似乎都会延迟图层树暂停的时间.因此,例如,如果其中一个块的延迟为1秒,并且图层树暂停3秒,则动画在恢复后会延迟4秒.我猜这与beginTime属性有关？任何帮助,将不胜感激.
// Pause and Resume methods,right from the technical Q&A
- (void)pauseAnimationsOnLayer:(CALayer *)layer
{
CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
layer.speed = 0.0;
layer.timeOffset = pausedTime;
}
- (void)resumeAnimationsOnLayer:(CALayer *)layer
{
CFTimeInterval pausedTime = [layer timeOffset];
layer.speed = 1.0;
layer.timeOffset = 0.0;
layer.beginTime = 0;
CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
layer.beginTime = timeSincePause;
}
// Chained animations
- (void)animateNextPopup
{
[UIView animateWithDuration:kRFPVictorySequenceStatePopupDuration
animations:^{
[_currentStateImageView setHidden:NO];
[_currentStateImageView setTransform:CGAffineTransformIdentity];
}
completion:^(BOOL finished) {
[UIView animateWithDuration:kRFPVictorySequenceStateSlideOffDuration
delay:kRFPVictorySequenceStateVoteDelay
options:UIViewAnimationOptionCurveEaseInOut
animations:^{
if (winnerIsDem) {
[_currentStateImageView setFrame:CGRectMake(-_currentStateImageView.frame.size.width,_currentStateImageView.frame.origin.y,_currentStateImageView.frame.size.width,_currentStateImageView.frame.size.height)];
}
else {
[_currentStateImageView setFrame:CGRectMake(1024,_currentStateImageView.frame.size.height)];
}
}
completion:^(BOOL finished) {
// Do some stuff
}
];
}
];
}
解决方法
我建议采用不同的方法.
动画块很容易实现,但只有在您不需要对动画进行任何控制时才有用.
否则,您应该使用计时器并手动创建自己的动画.
[NSTimer scheduledTimerWithTimeInterval:0.1
target:self
selector:@selector(timerFired)
userInfo:nil
repeats:YES];
- (void)timerFired
{
if (isPaused) {
// Do nothing
} else {
// Animate
}
}
- (IBAction)pauseTapped:(id)sender
{
if (isPaused) {
isPaused = NO;
} else {
isPaused = YES;
}
}
isPaused是一个控制动画状态的标志.
