ios - subview 背景颜色没有动画

Question

我有一个 UIViewController，其中包含一个呈现波形的 subview 。当按下按钮时，我试图让主 UIView、 subview 和导航栏从白色变为灰色。我已经能够更改主视图和导航栏，但无法弄清楚如何更改波形的 subview 。现在， subview 立即变为灰色，而不是与其他 View 和导航栏同步动画。

//View Controller Code

UIView.animate(withDuration: 10.0, animations: {

    self.navigationController?.navigationBar.barTintColor = UIColor(red: 20.00/255, green: 20.00/255, blue: 20.00/255, alpha: 1.00)
    self.navigationController?.navigationBar.layoutIfNeeded()
    self.waveform.backgroundColor = UIColor(red: 20.00/255, green: 20.00/255, blue: 20.00/255, alpha: 1.00)
    self.view.backgroundColor = UIColor(red: 20.00/255, green: 20.00/255, blue: 20.00/255, alpha: 1.00)

    }, completion: { finished in

         //do stuff
 })

//waveform view

override init(frame: CGRect) {
    super.init(frame: frame)
    self.setup()
}

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
    self.setup()
}

override func draw(_ rect: CGRect) {
    for i in 0..<self.circles.count {
        self.draw(self.circles[i], ratio: -1.0)
        self.draw(self.circles[i], ratio: 1.0)
    }
}

func update(_ level: Double) {

    amplitude = fmin(normalizedPowerLevelFromDecibels(level), maxAmplitude)
    setNeedsDisplay()
}

//更新动画

UIView.transition(with: self.view, duration: 1.0, options: [.transitionCrossDissolve], animations: {

    self.view.backgroundColor = UIColor(red: 20.00/255, green: 20.00/255, blue: 20.00/255, alpha: 1.00)


    self.navigationController?.navigationBar.barTintColor = UIColor(red: 20.00/255, green: 20.00/255, blue: 20.00/255, alpha: 1.00)
    self.navigationController?.navigationBar.layoutIfNeeded()

    self.waveform.backgroundColor = UIColor(red: 20.00/255, green: 20.00/255, blue: 20.00/255, alpha: 1.00)

}, completion: nil)

这会导致波形 View 和导航栏同步动画，但在其他两个 View 完成动画后，self.view 立即变为深灰色...

Answer 1

我做动画的想法是这样的

Objective-C

//Set Initial frame or color here & then write block for animation

 [UIView animateWithDuration:1.0f animations:^{

      // Now set your changing animation frame or color here

    }completion:^(BOOL finished) {

        //Do completion stuff here

    }];

如果你打算通过 anyView.layer.backgroundColor 设置它然后#import <QuartzCore/QuartzCore.h>

swift

//Set Initial frame or color here & then write block for animation

UIView.animate(withDuration: 5.0, animations: {

      // Now set your changing animation frame or color here
      self.view.layer.backgroundColor = UIColor(red: 20.00/255, green: 20.00/255, blue: 20.00/255, alpha: 1.00).cgColor

}, completion: { finished in

            //do completion stuffs
    })

如果你打算通过 anyView.layer.backgroundColor 设置它然后import QuartzCore