修改后的代码

Question

我想为UIView添加摇动效果，但我失败了。我的代码是

    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？

更新

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。这是我编辑过的代码，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： frame属性无法直接设置动画。

来自the documentation of the frame property on CALayer：

注意： frame属性无法直接设置动画。相反，您应该为bounds，anchorPoint和position属性的适当组合制作动画，以获得所需的结果。

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。

其他评论

NSValue

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

动画块

正如评论中已经说过的那样：在进行隐式动画时，你应该只将Core Animation和动画块组合在一起（因为它们会禁用视图）。你正在做的是显式动画，所以没有必要这样做。

`addAnimation:forKey:`

中的“密钥”

一种常见的误解是，添加动画时传递的关键字是您要更改的属性。事实并非如此。 keyPath已在动画上配置。

该密钥用于让您能够使用animationForKey:向图层询问已添加到其中的动画。如果您打算向图层询问，我建议您为其添加更具描述性的字符串。否则你可以通过nil。

修改后的代码

我已根据这些评论修改了您的代码

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

Answer 2

试试此代码

CABasicAnimation *theRotateAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
[theRotateAnimation setDuration:0.2f];
theRotateAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
[theRotateAnimation setRepeatCount:CGFLOAT_MAX];
[theRotateAnimation setAutoreverses:YES];
[theRotateAnimation setFromValue:[NSNumber numberWithFloat:(- 2 * (M_PI / 180))]];
[theRotateAnimation setToValue:[NSNumber numberWithFloat:(2 * (M_PI / 180))]];
[self.boView.layer setAnchorPoint:CGPointMake(0.5, 0.5)];
[self.boView.layer addAnimation:theRotateAnimation forKey:@"RotateAnimation"];

这肯定会动摇你的观点。

Answer 3

试试这个，摇动视图动画的简单代码

CABasicAnimation *shake = [CABasicAnimation animationWithKeyPath:@"position"];
    [shake setDuration:0.2];
    [shake setRepeatCount:4];
    [shake setAutoreverses:YES];
    [shake setFromValue:[NSValue valueWithCGPoint:
                         CGPointMake(View.center.x - 5,View.center.y)]];
    [shake setToValue:[NSValue valueWithCGPoint:
                       CGPointMake(View.center.x + 5, View.center.y)]];
    [View.layer addAnimation:shake forKey:@"position"];

关键帧动画失败

3 个答案:

其他评论

NSValue

动画块

`addAnimation:forKey:`

修改后的代码