Question

我正在尝试使用标记UIView animateWithDuration:链接一组UIViewAnimationOptionRepeat 我想重复的动画步骤是：

向左侧UIView 100个像素设置动画
淡出UIView（不透明度'0'）
逐渐淡出（不可见），将其移回原位（向右100 px）
淡化UIView（将不透明度设置为'1'）
使用标记UIViewAnimationOptionRepeat

我无法重复整个动画链 - 只能重复最顶层的动画。

我尝试的代码是：

[UIView animateWithDuration:1 delay:0 options:UIViewAnimationOptionRepeat animations:^{
        self.handImageView.frame = CGRectMoveByXPixels(self.handImageView.frame, -100);
        [UIView animateWithDuration:0.5 delay:1 options:0 animations:^{
            self.handImageView.alpha = 0;
        } completion:^(BOOL finished) {
            self.handImageView.frame = CGRectMoveByXPixels(self.handImageView.frame, 100);
            [UIView animateWithDuration:0.5 delay:0 options:0 animations:^{
                self.handImageView.alpha = 1;
            } completion:^(BOOL finished) {

            }];
        }];
    } completion:^(BOOL finished) {

    }];

Answer 1

问题是使用UIViewAnimationOptionRepeat的动画永远不会完成，因此永远不会调用completion块。但是，您可以使用performSelector方法重复动画，如下面的代码所示。

- (void)repeatingAnimationForView:(UIView *)view
{
    [UIView animateWithDuration:1 delay:0 options:0
    animations:^{ view.frame = CGRectMoveByXPixels(view.frame, -100); }
    completion:^(BOOL finished) {  if ( finished )  {

    [UIView animateWithDuration:0.5 delay:0 options:0
    animations:^{ view.alpha = 0; }
    completion:^(BOOL finished) {  if ( finished )  {

    view.frame = CGRectMoveByXPixels(view.frame, 100);

    [UIView animateWithDuration:0.5 delay:0 options:0
    animations:^{ view.alpha = 1; }
    completion:^(BOOL finished) {  if ( finished )  {

    if ( self.enableRepeatingAnimation )
        [self performSelector:@selector(repeatingAnimationForView:) withObject:view afterDelay:0];

    }}]; }}]; }}];
}

- (void)stopRepeatingAnimationForView:(UIView *)view
{
    self.enableRepeatingAnimation = NO;
    [view.layer removeAllAnimations];
    view.frame = CGRectMake( 100, 137, 80, 50 );
    view.alpha = 1;
}

- (void)startRepeatingAnimationForView:(UIView *)view
{
    self.enableRepeatingAnimation = YES;
    [self repeatingAnimationForView:view];
}

要立即停止动画，请调用上面显示的stopRepeatingAnimationForView方法。要在周期结束时停止动画，只需将self.enableRepeatingAnimation设置为NO即可。

如何使用UIViewAnimationOptionRepeat自动重复一组链式UIView动画

1 个答案: