使用动画更改UIView背景颜色

我想用过渡动画改变我的UIView背景颜色。 例如，如果视图为红色，我将其更改为蓝色。 蓝色将从屏幕底部向上滑动到顶部并填满整个屏幕。 我想通过制作具有所需颜色的相同尺寸的UIView ，然后从屏幕上直到顶部制作动画来实现这一点。 尽管如此，这似乎并不是一种非常优雅的方式。 有没有更好的方法呢？ 任何积分都会非常感激。 谢谢！

Answer 1

尝试这个：

 CALayer *layer = [CALayer layer]; layer.frame = CGRectMake(0, self.view.bounds.size.height, self.view.bounds.size.width, self.view.bounds.size.height); layer.backgroundColor = [UIColor blueColor].CGColor; [self.view.layer addSublayer:layer]; CABasicAnimation *animation = [CABasicAnimation animation]; animation.keyPath = @"position.y"; animation.byValue = @(-self.view.bounds.size.height); animation.duration = 1; animation.fillMode = kCAFillModeForwards; animation.removedOnCompletion = NO; [layer addAnimation:animation forKey:@"Splash"]; 

你可以试试这个：

 [UIView beginAnimations:nil context:nil]; [UIView setAnimationDuration:2.0]; [UIView setAnimationTransition:UIViewAnimationTransitionCurlUp forView:self.view cache:NO]; self.view.layer.backgroundColor = [UIColor blueColor].CGColor; [UIView commitAnimations]; 

我还有另一个建议，使过渡顺利：

 [UIView animateWithDuration:2.0 animations:^{ self.view.layer.backgroundColor = [UIColor blueColor].CGColor; } completion:nil]; 

Answer 2

你可以：

• 正如您所提到的，使用另一个UIView作为动画的中间体。 它不那么优雅，但它的工作原理和简单。
• 使用CALayer ，如果你搜索它，你可以找到许多简单的例子，例如，来自Ray Wenderlich ，我觉得很棒。

UPDATE

我自己使用CAShapeLayer创建了这个效果，并且我还使用UIView动画创建了效果。 以下是片段，评论和随意修改：

的UIView

 - (void)changeColorWithFillingAnimation { //we create a view that will increase in size from top to bottom, thats why it starts with these frame parameters UIView *fillingView = [[UIView alloc] initWithFrame:CGRectMake(0, self.view.bounds.size.height - 1, self.view.bounds.size.width, 1)]; //set the color we want to change to fillingView.backgroundColor = [UIColor blueColor]; //add it to the view we want to change the color [self.view addSubview:fillingView]; [UIView animateWithDuration:2.0 animations:^{ //this will make so the view animates up, since its animating the frame to the target view's size fillingView.frame = self.view.bounds; } completion:^(BOOL finished) { //set the color we want and then disappear with the filling view. self.view.backgroundColor = [UIColor blueColor]; [fillingView removeFromSuperview]; }]; } 

CAShapeLayer + CABasicAnimation + CATransition

 - (void)changeColorWithShapeLayer { //create the initial and the final path. UIBezierPath *fromPath = [UIBezierPath bezierPathWithRect:CGRectMake(0, self.view.bounds.size.height - 1, self.view.bounds.size.width, 1)]; UIBezierPath *toPath = [UIBezierPath bezierPathWithRect:CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height)]; //create the shape layer that will be animated CAShapeLayer *fillingShape = [CAShapeLayer layer]; fillingShape.path = fromPath.CGPath; fillingShape.fillColor = [UIColor blueColor].CGColor; //create the animation for the shape layer CABasicAnimation *animatedFill = [CABasicAnimation animationWithKeyPath:@"path"]; animatedFill.duration = 2.0f; animatedFill.fromValue = (id)fromPath.CGPath; animatedFill.toValue = (id)toPath.CGPath; //using CATransaction like this we can set a completion block [CATransaction begin]; [CATransaction setCompletionBlock:^{ //when the animation ends, we want to set the proper color itself! self.view.backgroundColor = [UIColor blueColor]; }]; //add the animation to the shape layer, then add the shape layer as a sublayer on the view changing color [fillingShape addAnimation:animatedFill forKey:@"path"]; [self.view.layer addSublayer:fillingShape]; [CATransaction commit]; }