当其子视图按比例放大时，ScrollView 不会滚动

Question

I have a LinearLayoutCompat inside my ScrollView :

<ScrollView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="8dp"
        app:layout_constraintBottom_toTopOf="@id/overview_holder"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <androidx.appcompat.widget.LinearLayoutCompat
            android:id="@+id/seats_viewHolder"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical" />

    </ScrollView>

The LinearLayoutCompat fits inside the ScrollView perfectly; the problem is that when I try to scale up the LinearLayoutCompat programmatically, the ScrollView still doesn't start scrolling. How can I update the ScrollView so that it scrolls and shows the parts of its child view that have gone outside the screen?

Answer 1

Since I don't have more detail about how you scale up the LinearLayoutCompat programmatically, so there is no any clues to see what's going on for that part.

However I notice that you set the layout_width and layout_height as 0dp , which maybe can change to match_parent or wrap_content .

Here is a snapshot of code which I add the ImageView into LinearLayoutCompat programmatically to mimic the scale up and the scrollview can be scrolled

<ScrollView
        android:id="@+id/scrollview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginBottom="8dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <androidx.appcompat.widget.LinearLayoutCompat
            android:id="@+id/seats_viewHolder"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical" />

</ScrollView>

override fun onCreate(savedInstanceState: Bundle) {
    val linearLayoutCompat = findViewById<LinearLayoutCompat>(R.id.seats_viewHolder)
    for (i in 0 .. 100) {
        val imageView = ImageView(this).apply {
            setImageResource(R.drawable.ic_launcher_background)
        }
        linearLayoutCompat.addView(imageView)
    }
}