ios - 动画 ios 应用程序中的黑色过渡

Question

在我的场景转换之间，丑陋的黑色背景短暂出现。有人告诉我，删除动画和延迟可以防止这种情况发生，但这并没有奏效。

它只会影响测验问题之间的转换 - 应用中的其他页面都可以。这些问题的 json 文件是后端。

这里是题目展示engine.m的动画代码

-(void)attachDelegate:(id<QuestionViewControllerDelegate>)delegate{
self.questionController1.delegate = delegate;
self.questionController2.delegate = delegate;
 }

-(BOOL)showNextQuestion:(NSArray*)questions inMainView:(UIView*)mainView{

 if(self.nextIndex < questions.count){

    QuestionViewController* controller = self.nextIndex % 2 == 0 ? 

 self.questionController1 : self.questionController2;
    QuestionViewController* currentController = self.nextIndex % 2 == 1 ? 
  self.questionController1 : self.questionController2;

    controller.question = questions[self.nextIndex];

    if(self.nextIndex == 0){

        [controller.view setTranslatesAutoresizingMaskIntoConstraints:NO];
        [mainView addSubview:controller.view];
        ConstraintsPackage* controllerPackage = [self 
 addConstraintsToSuperview:mainView subview:controller.view];
        controller.view.tag = 0;


        [currentController.view 
setTranslatesAutoresizingMaskIntoConstraints:NO];
        [mainView addSubview:currentController.view];
        ConstraintsPackage* currentControllerPackage = [self 
    addConstraintsToSuperview:mainView   

 subview:currentController.view];           
 currentController.view.tag = 1;

        self.constraintPackages = @[controllerPackage, 
currentControllerPackage];
    }

    [controller loadData];
    [self removeController:currentController andShowController:controller 
inMainView:mainView];


    self.nextIndex++;
    return YES;
}else{

    [self.questionController1.view removeFromSuperview];
    [self.questionController2.view removeFromSuperview];
    return NO;
}


}

-(void)removeController:(UIViewController*)fromViewController 
andShowController:(UIViewController*)toViewController inMainView:
(UIView*)mainView{

NSTimeInterval duration = 0.3;

ConstraintsPackage* fromPackage = (ConstraintsPackage*)self.constraintPackages[fromViewController.view.tag];

ConstraintsPackage* toPackage = (ConstraintsPackage*)self.constraintPackages[toViewController.view.tag];

CGFloat toValue =  0;
CGFloat fromValue = mainView.frame.size.width;
[mainView layoutIfNeeded];

[UIView animateWithDuration:duration animations:^{

    fromPackage.centerXConstraint.constant = -fromValue;
    toPackage.centerXConstraint.constant = toValue;
    [mainView layoutIfNeeded];

} completion:^(BOOL finished) {

    fromPackage.centerXConstraint.constant = 2*mainView.frame.size.width;
}];

if (SYSTEM_VERSION_LESS_THAN(@"8.0")) {
    [fromViewController viewDidAppear:YES];
    [toViewController viewDidAppear:YES];
}

这是来自 dropanimationcontroller.m 的代码

@implementation DropAnimationController

-(id)init{
self = [super init];

if(self){

    self.presentationDuration = 0.6;
    self.dismissalDuration = 0.6;
}

return self;
}

-(NSTimeInterval)transitionDuration:           
    (id<UIViewControllerContextTransitioning>)transitionContext{

return self.isPresenting ? self.presentationDuration :  
    self.dismissalDuration;

}

-(void)animateTransition:   
    (id<UIViewControllerContextTransitioning>)transitionContext{

if(self.isPresenting){
    [self executePresentationAnimation:transitionContext];
}
else{
    [self executeDismissalAnimation:transitionContext];
}

}

-(void)executePresentationAnimation:    
(id<UIViewControllerContextTransitioning>)transitionContext{

UIView* inView = [transitionContext containerView];

UIViewController* toViewController = [transitionContext 
viewControllerForKey:UITransitionContextToViewControllerKey];

UIViewController* fromViewController = [transitionContext 
viewControllerForKey:UITransitionContextFromViewControllerKey];

UIView* blurredView = [self getBlurredImage:fromViewController.view];
blurredView.alpha = 0.0;
[inView addSubview:blurredView];

[inView addSubview:toViewController.view];

CGPoint centerOffScreen = inView.center;

centerOffScreen.y = (-1)*inView.frame.size.height;
toViewController.view.center = centerOffScreen;

[UIView animateWithDuration:self.presentationDuration delay:0.0f 
usingSpringWithDamping:0.4f initialSpringVelocity:6.0f 
options:UIViewAnimationOptionCurveEaseIn animations:^{

    toViewController.view.center = inView.center;
    fromViewController.view.alpha = 0.6;
    blurredView.alpha = 1.0;

} completion:^(BOOL finished) {

    [transitionContext completeTransition:YES];
}];
}

-(void)executeDismissalAnimation:
(id<UIViewControllerContextTransitioning>)transitionContext{

UIView* inView = [transitionContext containerView];

UIViewController* toViewController = [transitionContext 
viewControllerForKey:UITransitionContextToViewControllerKey];

UIViewController* fromViewController = [transitionContext 
viewControllerForKey:UITransitionContextFromViewControllerKey];

UIView* blurredView = [self getBlurredImage:toViewController.view];
blurredView.alpha = 1.0;
[inView addSubview:blurredView];

[inView insertSubview:toViewController.view 
belowSubview:fromViewController.view];

CGPoint centerOffScreen = inView.center;
centerOffScreen.y = (-1)*inView.frame.size.height;

[UIView animateKeyframesWithDuration:self.dismissalDuration delay:0.0f
 options:UIViewKeyframeAnimationOptionCalculationModeLinear animations:^{

    [UIView addKeyframeWithRelativeStartTime:0 relativeDuration:0.5 
animations:^{

        CGPoint center = fromViewController.view.center;
        center.y += 50;
        fromViewController.view.center = center;
        blurredView.alpha = 0.0;
    }];

    [UIView addKeyframeWithRelativeStartTime:0.5 relativeDuration:0.5 
animations:^{

        fromViewController.view.center = centerOffScreen;
        toViewController.view.alpha = 1.0;

    }];


} completion:^(BOOL finished) {
    [transitionContext completeTransition:YES];
}];
}


-(UIView*)getBlurredImage:(UIView*)view{
UIGraphicsBeginImageContext(view.frame.size);
[view drawViewHierarchyInRect:view.frame afterScreenUpdates:YES];
UIImage* image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

UIImage* blurredImage = [image applyBlurWithRadius:2.0 tintColor:[UIColor
colorWithWhite:0.0 alpha:0.4f] saturationDeltaFactor:1 maskImage:nil];

UIImageView* imageView = [[UIImageView alloc] initWithFrame:view.frame];
imageView.image = blurredImage;

return imageView;

}


@end

Answer 1

我认为它采用了窗口的背景颜色。请试试这个，它可能对你有帮助。

self.window.backgroundColor=[UIColor whiteColor];