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我使用 CoreAnimation 为 UIImageView 设置动画（曲线贝塞尔动画）。这是我的代码：

CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
pathAnimation.calculationMode = kCAAnimationCubic;
pathAnimation.fillMode = kCAFillModeForwards;
pathAnimation.removedOnCompletion = NO;

CGPoint endPoint = originalPosition;

UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:star.layer.position];
[path addQuadCurveToPoint:endPoint controlPoint:CGPointMake(star.layer.position.x, endPoint.y)];

pathAnimation.path = path.CGPath;

[star.layer addAnimation:pathAnimation forKey:@"moveToScorebarAnimation"];

结果，我得到了带有堆栈跟踪的EXC_BAD_ACCESS (code=2, address=0x0)：

CoreGraphics`CG::Path::apply(void*, void (*)(void*, CGPathElementType, CGPoint const*)) const:
0x613c06:  pushl  %ebp
0x613c07:  movl   %esp, %ebp
0x613c09:  subl   $24, %esp
0x613c0c:  movl   8(%ebp), %eax
0x613c0f:  movl   (%eax), %ecx
0x613c11:  movl   (%ecx), %eax
0x613c13:  movl   16(%ebp), %edx
0x613c16:  movl   %edx, 8(%esp)
0x613c1a:  movl   12(%ebp), %edx
0x613c1d:  movl   %edx, 4(%esp)
0x613c21:  movl   %ecx, (%esp)
0x613c24:  calll  *64(%eax)
0x613c27:  addl   $24, %esp
0x613c2a:  popl   %ebp
0x613c2b:  ret

我尝试使用不同的手册来执行此操作，但应用程序崩溃的方式相同。不明白我的错在哪里。任何帮助将不胜感激，谢谢。

PS这里有一个类似的bug，可惜只是去掉动画就解决了。

PPS 弧已启用。另外，如果我评论pathAnimation.path = path.CGPath; 线，没有出现崩溃，以及动画（并不奇怪:)）。

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2 回答 2

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That error will be thrown when the object doesn't exist in memory. Make sure you initialization is proper way ?? make sure you initialize Layer..etc.. ?

Best way is use BreakPoint to find out where your application get crush ??

I'm not sure but it may be helpful for you.

Add your animation as

CAAnimationGroup *group = [CAAnimationGroup animation];
group.animations = [NSArray arrayWithObjects: pathAnimation,nil];
group.duration = 7.0;  //The total time of the animations, don't know if redundant
group.delegate = self;

[self.layer addAnimation:group forKey:@"path"];
于 2013-08-03T13:54:58.380 回答
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用 CABasicAnimation 替换 CAKeyframeAnimation：

 CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:@"position"];
 pathAnimation.fromValue = [NSValue valueWithCGPoint:star.layer.position];
 pathAnimation.toValue = [NSValue valueWithCGPoint:endPoint];
 pathAnimation.fillMode = kCAFillModeForwards;
 pathAnimation.removedOnCompletion = NO;

好像是苹果的bug

于 2013-08-12T21:30:45.367 回答