Ios UIview Flip使视图变暗

我在iOS中实现了一个简单的FlipView：一个包含两个子视图的UIView，一次显示一个子视图，当你点击它时，它会翻转它们。 我使用下面的动画来设置翻转的动画

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
    @synchronized(self){
        if(!self.flipping){
            self.flipping = YES;
            UIView *toView = self.currentView == self.primaryView ? self.secondaryView : self.primaryView;            
            [UIView transitionFromView:self.currentView toView:toView duration:self.speed options:UIViewAnimationOptionTransitionFlipFromLeft|UIViewAnimationOptionCurveEaseInOut completion:^(BOOL finished) {
                [self.currentView removeFromSuperview];
                self.currentView = toView;
                self.flipping = NO;
            }];                
        }
    }
}

很直接，对吧

但让我不安的是，当视图翻转时，翻转的内容变暗了。这表明，在光背景下

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有没有人知道一个解决方案可以有完全相同的动画，但没有变暗（我最近遇到了一个类似症状的问题，每当我执行某个操作时，我都会在代码的其他地方一次又一次地添加子视图。也许你正在做类似的事情？当触摸结束时，你正在对翻转的内容做其他事情吗？如果是这样，你可能需要删除正在添加的子视图你的问题

我成功了，从我在这里找到的代码中获得了灵感（他自己也从中获得了灵感）

无论如何，我所做的是在两个视图之间旋转

- (void)flip{
    @synchronized(self){
        if(!self.flipping){
            self.flipping = YES;

            UIView *bottomView = self.currentView == self.primaryView ? self.secondaryView : self.primaryView;
            CALayer *top = self.currentView.layer;
            CALayer *bot = bottomView.layer;

            CAAnimation *topAnimation = [self flipAnimationWithDuration:self.speed/2.0 forLayerBeginningOnTop:YES scaleFactor:1];
            CAAnimation *bottomAnimation = [self flipAnimationWithDuration:self.speed/2.0 forLayerBeginningOnTop:NO scaleFactor:1];

            CGFloat zDistance = 1500.0f;
            CATransform3D perspective = CATransform3DIdentity;
            perspective.m34 = -1. / zDistance;
            top.transform = perspective;
            bot.transform = perspective;

            topAnimation.delegate = self;
            [CATransaction setCompletionBlock:^{
                [top removeAllAnimations];
                [self.currentView removeFromSuperview];
                self.currentView = bottomView;
                [self addSubview:bottomView];

                [CATransaction setCompletionBlock:^{
                    self.flipping = NO;
                    [bot removeAllAnimations];
                }];
                [CATransaction begin];

                [bot addAnimation:bottomAnimation forKey:@"flip"];

                [CATransaction commit];
            }];
            [CATransaction begin];
            [top addAnimation:topAnimation forKey:@"flip"];

            [CATransaction commit];
        }
    }
}

-(CAAnimation *)flipAnimationWithDuration:(NSTimeInterval)aDuration forLayerBeginningOnTop:(BOOL)beginsOnTop scaleFactor:(CGFloat)scaleFactor
{
    // Rotating halfway (pi radians) around the Y axis gives the appearance of flipping
    CABasicAnimation *flipAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.y"];
    CGFloat startValue = beginsOnTop ? 0.0f : M_PI/2;
    CGFloat endValue = beginsOnTop ? -M_PI/2 : 0.0f;
    flipAnimation.fromValue = [NSNumber numberWithDouble:startValue];
    flipAnimation.toValue = [NSNumber numberWithDouble:endValue];

    // Shrinking the view makes it seem to move away from us, for a more natural effect
    // Can also grow the view to make it move out of the screen
    CABasicAnimation *shrinkAnimation = nil;
    if (scaleFactor != 1.0 ) {
        shrinkAnimation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
        shrinkAnimation.toValue = [NSNumber numberWithFloat:scaleFactor];

        // We only have to animate the shrink in one direction, then use autoreverse to "grow"
        shrinkAnimation.duration = aDuration * 0.5;
        shrinkAnimation.autoreverses = YES;
    }

    // Combine the flipping and shrinking into one smooth animation
    CAAnimationGroup *animationGroup = [CAAnimationGroup animation];
    animationGroup.animations = [NSArray arrayWithObjects:flipAnimation, shrinkAnimation, nil];

    // As the edge gets closer to us, it appears to move faster. Simulate this in 2D with an easing function
    animationGroup.timingFunction = [CAMediaTimingFunction functionWithName:beginsOnTop?kCAMediaTimingFunctionEaseIn:kCAMediaTimingFunctionEaseOut];
    animationGroup.duration = aDuration;

    // this really means keep the state of the object at whatever the anim ends at
    // if you don't do this then it reverts back to the original state (e.g. brown layer)
    animationGroup.fillMode = kCAFillModeForwards;
    animationGroup.removedOnCompletion = NO;

    return animationGroup;
}

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这两个视图分别命名为primaryView和secondaryView。您可以使用任何视图（图像视图、文本视图…

Hum，这可能不是问题所在，因为我在-（void）touchSedend:（NSSet*）touchWithEvent:（UIEvent*）中共享了我在-（void）touchSedend:（NSSet*）touchWithEvent中所做的所有操作事件…只是想知道，为什么要从超级视图中删除

self.currentView

？将

toView

引用到已从视图层次结构中删除的视图有什么用？如果可能没有用。我不确定。无论如何，我尝试了使用或使用了should，但它没有改变任何东西。。。