Kotlin旋转动画不工作.单击spinBtn时没有发生任何事情

Question

***我正在尝试创建一个spinningWheel动画，按下按钮后，我的imageView将旋转。我发现了一个youtube视频，里面有一些我转换成kotlin的java代码。根据下面的代码，按下按钮时不会发生任何事情。到目前为止，我已经在GameViewModel中使用了rotateAnimation类和一些计算，并在GameFragment类的onCreateView((中调用了spin((。

下面的代码是我用于rotateAnimation的两个类，但它似乎不起作用。我不确定问题出在哪一部分。有人知道吗？***

类GameViewModel:ViewModel((｛

private val fields = arrayOf("1","2","3","4","5","6","7")
private val fieldDegrees = IntArray(fields.size)
private var degree = 0
var isSpinning = false

fun getDegreesForSectors(){
val oneFieldsDegrees = 360/fields.size
for (i in fields.indices){
fieldDegrees[i] = (i+1) * oneFieldsDegrees
}
}

fun spin(imageView: ImageView){
isSpinning = true
degree = (0..fields.size).random()
val rotateAnimation = RotateAnimation(0.toFloat(),
(360 * fields.size + fieldDegrees[degree]).toFloat(),
RotateAnimation.RELATIVE_TO_SELF, 0.5f, RotateAnimation.RELATIVE_TO_SELF, 0.5f)
rotateAnimation.setDuration(3600)
rotateAnimation.setFillAfter(true)
rotateAnimation.setInterpolator(DecelerateInterpolator())
rotateAnimation.setAnimationListener(object : Animation.AnimationListener{
override fun onAnimationStart(animation: Animation) {}
override fun onAnimationEnd(animation: Animation) {
isSpinning = false
}
override fun onAnimationRepeat(animation: Animation) {}
})
imageView.startAnimation(rotateAnimation)
}

}

类GameFragment:Fragment((｛

private lateinit var gameViewModel: GameViewModel
private var _binding: GameFragmentBinding? = null
// This property is only valid between onCreateView and
// onDestroyView.
private val binding get() = _binding!!

override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
gameViewModel =
ViewModelProvider(this).get(GameViewModel::class.java)

val spinBtn: Button? = view?.findViewById(R.id.spinBtn)
val wheelImage: ImageView? = view?.findViewById(R.id.Spinning_Wheel)
gameViewModel.getDegreesForSectors()
spinBtn?.setOnClickListener() {
if (!gameViewModel.isSpinning) {
gameViewModel.spin(wheelImage!!)
}
}

_binding = GameFragmentBinding.inflate(inflater, container, false)
val root: View = binding.root
return root

}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}

}

Answer 1

您正在onCreateView((中访问片段view。这将返回null，因为还没有任何内容被膨胀。使用绑定变量访问视图。

override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
gameViewModel = ViewModelProvider(this).get(GameViewModel::class.java)
_binding = GameFragmentBinding.inflate(inflater, container, false)
gameViewModel.getDegreesForSectors()
binding.spinBtn.setOnClickListener() {
if (!gameViewModel.isSpinning) {
gameViewModel.spin(binding.spinningWheel)
}
}
return binding.root
}