为CALayer anchorPoint设置动画

Question

我已经成功地动画层的位置和变换(旋转)。

现在，我需要动画的anchorPoint，但所有的尝试都失败了！即使我这样做：

2012... App[6437:403] layer: 1, KeyPath: anchorPoint, fromValue: NSPoint: {1.05, 0.5}, toValue: NSPoint: {1.05, 0.5}, Duration: 2.5

这是在动画层之前卡住的NSLog。我得到的结果是图层在X轴上向左移动了太远，然后又回来了。和重复(因为自动反转已打开)。

关于层层次的注意: SuperLayer有三个子层，我在上面应用动画。

为什么？应该如何设置锚点的动画？

我的代码：

    NSArray* subKeyPath     = [keyPaths objectAtIndex:tag];
    NSArray* subToValue     = [toValues objectAtIndex:tag];
    NSArray* subDuration    = [durations objectAtIndex:tag];

    NSEnumerator* keyPathsEnum  = [subKeyPath objectEnumerator];
    NSEnumerator* toValuesEnum  = [subToValue objectEnumerator];
    NSEnumerator* durationsEnum = [subDuration objectEnumerator];

    NSString* keyPath;
    NSNumber* toValue;
    NSNumber* duration;

    while ((keyPath = [keyPathsEnum nextObject]) && (toValue = [toValuesEnum nextObject]) && (duration = [durationsEnum nextObject])) {
        CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:keyPath];

        id offsetToValue;
        if ([keyPath hasPrefix:@"position"]) {
        //I removed the position animation, since animating the anchorPoint should suffice
        } else if ([keyPath hasPrefix:@"anchorPoint"]) {
            //This was when I used anchorPoint.x float value         = [[subLayer valueForKeyPath:keyPath] floatValue] - ([toValue floatValue]/[[subLayer contents] size].width);
            offsetToValue       = [NSNumber valueWithPoint:CGPointMake(1.05, 0.5)];
            keyPath             = [keyPath substringToIndex:[keyPath length]-2];
        } else {
            offsetToValue       = toValue;
        }

...

        animation.toValue       = offsetToValue;
        animation.duration      = [duration floatValue];
        animation.fillMode      = kCAFillModeForwards;
        animation.repeatCount   = INFINITY;
        animation.autoreverses  = YES;
        animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

        [subLayer addAnimation:animation forKey:keyPath];

        //update the model

    }

我尝试动画"anchorPoint.x“keyPath，同样的结果是:(

最后注意，我正在编写一个可可应用程序，但动画的X值应该是完全相同的可可和可可触摸。

Answer 1

你不会相信的(就好像我从一开始就和你坐在一起一样)..

在不设置fromValue的情况下，位置和旋转动画可以正常工作。但是，要对锚点进行动画处理，需要将锚点fromValue设置为初始值！

animation.fromValue = [subLayer valueForKeyPath:keyPath];