搜索栏上方的动态文本

Question

我正在尝试设置动态文本，在拖动搜索栏时，您可以在拖动栏时看到该值。但我没有取得任何成功。

我在stackoverflow中尝试了一些帖子，但我无法做任何事情，它遵循我所处理的代码：

class AccountActivity : LoggedActivity<ViewAccountBinding, AccountViewModelKotlin>() {

    // BASE METHODS
....

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        var _testText = TextView(this)
        _testText.setTextColor(resources.getColor(R.color.black_75))

        var currentValue : Int = binding.seekbarAccount.progress

        binding.seekbarAccount.setOnSeekBarChangeListener(object : SeekBar.OnSeekBarChangeListener{
            override fun onProgressChanged(p0: SeekBar?, progress: Int, p2: Boolean) {
                currentValue = progress

                //just to show dynamic text above thumb of seekbar
                var value : Int = (progress * (binding.seekbarAccount.width - 2 * binding.seekbarAccount.thumbOffset))/binding.seekbarAccount.max
                _testText.text = ""+progress.toString()
                _testText.x = (binding.seekbarAccount.x + value +  binding.seekbarAccount.thumbOffset)/2
            }

            override fun onStartTrackingTouch(p0: SeekBar?) {
                //
            }

            override fun onStopTrackingTouch(p0: SeekBar?) {
                viewModel.fontSize = currentValue
                Toast.makeText(this@AccountActivity,currentValue.toString(),Toast.LENGTH_SHORT).show()
            }
        })
}

XML：

                    <SeekBar
                        android:id="@+id/seekbarAccount"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="@dimen/margin_large"
                        android:alpha="0.75"
                        android:max="25"
                        android:min="7"
                        android:progress="@{viewModel.fontSize}"
                        android:progressDrawable="@drawable/progress_seek_bar_settings"
                        android:splitTrack="false"
                        android:thumb="@drawable/thumb_seekbar_settins" />