我有一个动画块来执行一个简单的基于变换的动画,在完成时从其超级视图中删除有问题的视图.
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];}];
然后我使用Tech Q& A 1673 http://developer.apple.com/library/ios/#qa/qa1673/_index.html详细说明的代码
暂停动画.
-(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,此代码不会阻止执行完成代码.因此,为了防止代码执行,我将完成代码更改为：
completion:^(BOOL finished){if(finished == TRUE)[msgView removeFromSuperview];};
检查完成时== TRUE会阻止在动画块暂停时执行完成代码.如果在“取消暂停”动画之前现在超出持续时间,则不会执行完成代码.即在这种情况下,msgView仍然在superview中.
无论如何暂停/取消暂停与完成代码相关的动画和计时器(如果这是正在发生的事情)？
解决方法
正如我在上面的评论中所说,似乎没有问题.以下内容在iOS 5.1和6.1中进行了测试.
使用UIImageView * transView和UIButton *触发器创建故事板.这是班级：
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(2.5,1.0);
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;
}
按下触发按钮时,动画开始.再按一次,动画停止.等待10秒钟,然后再次按下按钮.动画继续并结束,并记录“完成”.