如何在 Kotlin 中不断改变背景颜色?

How to keep changing background color in Kotlin?

我想保持背景像迪斯科屏幕一样变化。 但是在这段代码中,只显示了蓝色。我应该如何解决才能改变颜色?

var bgColor = 1
        val bgDrawableIds = intArrayOf(
            R.drawable.purple,
            R.drawable.red,
            R.drawable.blue,
        )
        bgColor++
        disco_display.background = resources.getDrawable(bgDrawableIds[bgColor % bgDrawableIds.size])
    

xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <FrameLayout
        android:id="@+id/disco_display"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/white" />

</androidx.constraintlayout.widget.ConstraintLayout>

将其包装在协程中:

lifecycleScope.launch {
    while (true) {
        disco_display.background = resources.getDrawable(bgDrawableIds[++bgColor % bgDrawableIds.size])
        delay(200L)
    }
}