Question

我想在刷卡时改变视图的颜色，但我不知道如何进行动画颜色更改。我很感激你的帮助。

Answer 1

backgroundColor可动态开箱即用

[UIView animateWithDuration:0.5 delay:1.0 options: UIViewAnimationCurveEaseOut animations:^{
    //this is the animation block here
    myView.backgroundColor = newColor;
} completion:^(BOOL finished) {
    if (finished){
        NSLog(@"Colour animation complete!");
    }
}];

Answer 2

使用CALayer，如果你搜索它，你可以找到许多简单的例子，例如Ray Wenderlich，我觉得这很好。

<强>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];
}

实现此目的的一种非常简单的方法是使用UIView动画块。

[UIView animateWithDuration:1.0 animations:^{
    view.backgroundColor = [UIColor redColor];
}];

Answer 3

假设您已实施左滑动手势，

UISwipeGestureRecognizer * swipeleft=[[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipeleft:)];
swipeleft.direction=UISwipeGestureRecognizerDirectionLeft;
[self.view addGestureRecognizer:swipeleft];

//实施手势方法

-(void)swipeleft:(UISwipeGestureRecognizer*)gestureRecognizer 
{
   //Do what you want here
    [UIView animateWithDuration:.5
                     animations:^{
                       self.view.backgroundColor = [UIColor yellowColor];
                     }
                     completion:^(BOOL finished){
                         NSLog(@"completion block");
                     }];
}
}

UIView的动画变色

3 个答案: