关键帧动画失败

Question

我想为UIView添加摇动效果,但我失败了.我的代码也是

    CGRect rectL=CGRectMake(473, 473, 88, 88);
    CGRect rectR=CGRectMake(493, 473, 88, 88);
    NSValue *valueL = [NSValue value: &rectL
                         withObjCType:@encode(CGRect)];
    NSValue *valueR = [NSValue value: &rectR
                        withObjCType:@encode(CGRect)];
    NSArray *firstArray=@[valueL,valueR,valueL,valueR,valueL,valueR,valueL,valueR];

    [UIView animateWithDuration:2 animations:^{
        CAKeyframeAnimation * theAnimation;

        // Create the animation object, specifying the position property as the key path.
        theAnimation=[CAKeyframeAnimation animationWithKeyPath:@"frame"];
        theAnimation.values=firstArray;
        theAnimation.duration=5.0;
        theAnimation.calculationMode= kCAAnimationLinear;
        // Add the animation to the layer.
        [self.boView.layer addAnimation:theAnimation forKey:@"frame"];//boView is an outlet of UIView
    }completion:^(BOOL finished){

    }];

当我运行代码时,视图仍然没有抖动.为什么？

UPDATE

我必须使用关键帧动画,因为在视图抖动之后,它需要移动到另一个地方,然后摇动然后停止.这是我编辑的代码,但它仍然不起作用.为什么？

    CGRect rectL=CGRectMake(463, 473, 88, 88);
    CGRect rectR=CGRectMake(503, 473, 88, 88);
    NSValue *valueL = [NSValue value: &rectL
                         withObjCType:@encode(CGRect)];
    NSValue *valueR = [NSValue value: &rectR
                        withObjCType:@encode(CGRect)];
    NSArray *firstArray=@[valueL,valueR,valueL,valueR,valueL,valueR,valueL,valueR];



    CAKeyframeAnimation * theAnimation;

    // Create the animation object, specifying the position property as the key path.
    theAnimation=[CAKeyframeAnimation animationWithKeyPath:@"frame"];
    theAnimation.values=firstArray;
    theAnimation.duration=5.0;
    theAnimation.calculationMode= kCAAnimationLinear;
    // Add the animation to the layer.
    [self.boView.layer addAnimation:theAnimation forKey:@"frame"];

Answer 1

tl; dr:该frame属性不是直接可动画的.

从CALayer上的frame属性文档:

注意:该frame属性不能直接设置动画.相反,您应该为the 和properties 的适当组合设置动画bounds,以实现所需的结果.anchorPointposition

在你的例子中,你只是改变位置,所以即使你可以为框架设置动画,最好为位置设置动画.

其他言论

NSValue

而不是[NSValue value:&rect withObjCType:@encode(CGRect)]我更喜欢专业 [NSValue valueWithCGRect:rect](或[NSValue valueWithCGPoint:point]在这种情况下)

动画块

正如评论中已经说过的那样:当你进行隐式动画时,你应该只结合核心动画和动画块(否则它们会禁用视图).你正在做的是一个显式动画,所以没有必要这样做.

中的"关键" addAnimation:forKey:

一种常见的误解是,添加动画时传递的键是您正在更改的属性.事实并非如此.该keyPath上的动画已经配置.

该密钥用于您能够向图层询问已添加到其中的动画animationForKey:如果您打算向图层询问它我建议您为其提供更具描述性的字符串.否则你可以通过nil.

修改后的代码

我根据这些评论修改了下面的代码

CGPoint leftPoint  = CGPointMake(473, 473);
CGPoint rightPoint = CGPointMake(493, 473);

NSValue *leftValue  = [NSValue valueWithCGPoint:leftPoint];
NSValue *rightValue = [NSValue valueWithCGPoint:rightPoint];
NSArray *firstArray = @[leftValue, rightValue,
                        leftValue, rightValue,
                        leftValue, rightValue,
                        leftValue, rightValue];

CAKeyframeAnimation * theAnimation;

// Create the animation object, specifying the position property as the key path.
theAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
theAnimation.values = firstArray;
theAnimation.duration = 5.0;
theAnimation.calculationMode = kCAAnimationLinear;
// Add the animation to the layer.
[self.boView.layer addAnimation:theAnimation 
                         forKey:@"moveBackAndForth"]; //boView is an outlet of UIView