从Swift中的CABasicAnimation获取当前位置

Question

我设置了一个CABasicAnimation toValue和fromValue。

let translateAnimation = CABasicAnimation(keyPath: "transform.translation.x")
let targetFrame = CGRectOffset(runnerContentView.frame, targetX, 0);
let sourcePoint = CGPoint(x: startingvalue, y: 0)
translateAnimation.toValue = NSValue(point: targetFrame.origin)
translateAnimation.fromValue = NSValue(point: sourcePoint)

当我点击一个按钮时，我需要来自CABasicAnimation 的当前位置。