Android 按钮动画（具有ClipDrawable的TimeAnimator）无法正常工作

我想通过从左到右填充按钮背景来设置动画。我用。当我把它放在onCreate中时，它可以正常工作，但当用户在我的测验中选择正确答案时，我需要设置按钮的动画。 这是我的核对答案方法

fun checkAnswer(selectedAnswer: Button) {
        enableAnswersButton(false)
        if (selectedAnswer.text.toString() == listOfTests[currentQuestion].rightAnswer){
            val layerDrawable = selectedAnswer.background as LayerDrawable
            mClipDrawable =
                layerDrawable.findDrawableByLayerId(R.id.clip_drawable_false) as ClipDrawable

            mAnimator = TimeAnimator()
            mAnimator!!.setTimeListener(this)

            selectedAnswer.setOnClickListener {

                if (!mAnimator!!.isRunning) {
                    mCurrentLevel = 0;
                    mAnimator!!.start()
                }
            }
        } else {
            val layerDrawable = selectedAnswer.background as LayerDrawable
            mClipDrawable =
                layerDrawable.findDrawableByLayerId(R.id.clip_drawable_true) as ClipDrawable

            mAnimator = TimeAnimator()
            mAnimator!!.setTimeListener(this)


            selectedAnswer.setOnClickListener {

                if (!mAnimator!!.isRunning) {
                    mCurrentLevel = 0;
                    mAnimator!!.start()
                }
            }

问题是动画有时会工作。有时onTimeUpdate方法不被调用，动画也不起作用

  override fun onTimeUpdate(animation: TimeAnimator?, totalTime: Long, deltaTime: Long) {
        mClipDrawable!!.level = mCurrentLevel
        if (mCurrentLevel >= MAX_LEVEL) {
            mAnimator!!.cancel()
        } else {
            mCurrentLevel = min(MAX_LEVEL, mCurrentLevel + LEVEL_INCREMENT)
        }

    }

请帮忙，我已经查过了！。那里的实现很好，只是你不应该使用

  selectedAnswer.setOnClickListener {//<===this part need to be removed as its setting onClick which will work if next time same button is clicked 

            if (!mAnimator!!.isRunning) {
                mCurrentLevel = 0;
                mAnimator!!.start()
            }
        }

---

现在，由于此选项有一个动画师用于“正确”或“不正确”，因此将播放它。

为此，您需要将另一个动画师单独保存到正确答案，单击任何按钮并启动其动画师后，手动启动**正确按钮的**动画师

   firstOptionTextView.setText(Put the Option here);

   if (firstOptionTextView.text.toString() == listOfTests[currentQuestion].rightAnswer){
        val layerDrawable = selectedAnswer.background as LayerDrawable
        mClipDrawable =
            layerDrawable.findDrawableByLayerId(R.id.clip_drawable_false) as ClipDrawable

        mAnimator = TimeAnimator()
        mAnimator!!.setTimeListener(this)

        firstOptionTextView.setOnClickListener {

            if (!mAnimator!!.isRunning) {
                mCurrentLevel = 0;
                mAnimator!!.start()
            }
        }
    } else {
        val layerDrawable = selectedAnswer.background as LayerDrawable
        mClipDrawable =
            layerDrawable.findDrawableByLayerId(R.id.clip_drawable_true) as ClipDrawable

        mAnimator = TimeAnimator()
        mAnimator!!.setTimeListener(this)


        firstOptionTextView.setOnClickListener {

            if (!mAnimator!!.isRunning) {
                mCurrentLevel = 0;
                mAnimator!!.start()
            }
        }