iOS之UITextField输入错误的震动动画

 //左右震动效果
 - (void)shake:(UIView *)view {
 CGRect frame = view.frame;
 CAKeyframeAnimation *shakeAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];

 CGMutablePathRef shakePath = CGPathCreateMutable();
 CGPathMoveToPoint(shakePath, NULL, frame.origin.x+frame.size.width/, frame.origin.y+frame.size.height/);
 int index;
 for (index = ; index >=; --index) {
 CGPathAddLineToPoint(shakePath, NULL, frame.origin.x+frame.size.width/ - frame.size.width * 0.02f * index, frame.origin.y+frame.size.height/);
 CGPathAddLineToPoint(shakePath, NULL, frame.origin.x+frame.size.width/ + frame.size.width * 0.02f * index, frame.origin.y+frame.size.height/);
 }
 CGPathCloseSubpath(shakePath);

 shakeAnimation.path = shakePath;
 shakeAnimation.duration = 0.5f;
 shakeAnimation.removedOnCompletion = YES;

 [view.layer addAnimation:shakeAnimation forKey:nil];
 CFRelease(shakePath);
 }