使用 CABasicAnimation 为多个 CALayers 设置动画的问题

Question

我在我的棋盘游戏 iPhone 应用程序中遇到了很多动画问题。我使用以下函数为移动计数器的计算机播放器设置动画：

-(void)animateCounterMoveFor:(int)playerType counterId:(int)countId {

    // set up the move to an end point
    CABasicAnimation *move = [CABasicAnimation animationWithKeyPath:@"position"];
    [move setDuration:3.5];
    [move setToValue:[NSValue valueWithCGPoint:CGPointMake((xPos), (yPos))]];
    [move setFillMode:kCAFillModeForwards];
    [move setRemovedOnCompletion:NO];
    CAMediaTimingFunction *tf = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    [move setTimingFunction:tf];

    // enable the animation stop to set layer to right position
    [move setValue:[NSNumber numberWithInt:countId] forKey:@"counterId"];
    [move setValue:[NSNumber numberWithInt:playerType] forKey:@"playerType"];
    [move setDelegate:self];

    // add move to the layer
    [layer addAnimation:move forKey:@"moveAnimation"];

}

.. 然后委托设置图层位置并在动画完成时移除动画（否则计数器会移回其起始位置）。

-(void)animationDidStop:(CABasicAnimation *)anim finished:(BOOL)flag {

    NSNumber *counterId = [anim valueForKey:@"counterImageId"];
    NSNumber *playerId = [anim valueForKey:@"playerType"];

    int countId = [counterId intValue];
    int playId = [playerId intValue];

// code here gets position information using counter and player id

    // set the final position of the layer when the anim stops, then remove the anim
    [layer setPosition:CGPointMake(xPos, yPos)];
    [layer removeAnimationForKey:@"moveAnimation"];

}

当一个计数器移动时，这一切都很好，但是当一个计数器带另一个计数器时，我使用相同的方法来移动两者。我认为动画的副本已传递给图层，因此我可以调用它来移动第一个计数器图层，然后立即再次调用它以移动第二个。我注销了对象 ID 并创建了两个不同的移动动画，但只有第二个计数器移动。 animationDidStop：被调用两次，每次都传递正确的计数器信息。

关于如何使它工作的任何想法？我已经浏览了很多 CAAnimation/CALayer 问题，所以我想这不仅仅是我遇到的问题；）

Answer 1

为什么不提前知道最终的位置？

我会在 animateCounterMoveFor: 方法中设置对象的位置，否则它会迅速回到原始位置，因为在你设置它之前，calayer 不会真正移动。

-(void)animateCounterMoveFor:(int)playerType counterId:(int)countId {

    // set up the move to an end point
    CABasicAnimation *move = [CABasicAnimation animationWithKeyPath:@"position"];
    [move setDuration:3.5];
    [move setToValue:[NSValue valueWithCGPoint:CGPointMake((xPos), (yPos))]];
    [move setFillMode:kCAFillModeForwards];
    [move setRemovedOnCompletion:NO];
    CAMediaTimingFunction *tf = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    [move setTimingFunction:tf];


    [layer addAnimation:move forKey:@"position"];   // Replaces the previous position animation on the layer
    [layer setPosition:CGPointMake(xPos, yPos)];        // Sets the final position after animation is finished

    // enable the animation stop to set layer to right position
    [move setValue:[NSNumber numberWithInt:countId] forKey:@"counterId"];
    [move setValue:[NSNumber numberWithInt:playerType] forKey:@"playerType"];
    [move setDelegate:self];

}