android - 如何使用带有底部导航 View 的全屏 fragment ？

Question

我想在基于按钮导航的布局中使用全屏 fragment 。问题是内容没有填满隐藏的导航空间。我的目标是让它在没有导航或状态栏的情况下填满整个屏幕。

Screenshot: result

Activity xml:

<com.flipboard.bottomsheet.BottomSheetLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/bottomsheet"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/container"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@+id/nav_view"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="0dp"
            android:layout_marginEnd="0dp"
            android:background="?android:attr/windowBackground"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:menu="@menu/bottom_nav_menu" />

        <fragment
            android:id="@+id/nav_host_fragment"
            android:name="androidx.navigation.fragment.NavHostFragment"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            app:defaultNavHost="true"
            app:layout_constraintBottom_toTopOf="@id/nav_view"
            app:layout_constraintHorizontal_bias="0.0"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.0"
            app:navGraph="@navigation/mobile_navigation" />

    </androidx.constraintlayout.widget.ConstraintLayout>
</com.flipboard.bottomsheet.BottomSheetLayout>

fragment 代码:(来自 Android Studio 的全屏 fragment 模板)

class FullscreenFragment : Fragment() {
    private val hideHandler = Handler()
    @Suppress("InlinedApi")
    private val hidePart2Runnable = Runnable {
        // Delayed removal of status and navigation bar

        // Note that some of these constants are new as of API 16 (Jelly Bean)
        // and API 19 (KitKat). It is safe to use them, as they are inlined
        // at compile-time and do nothing on earlier devices.
        val flags =
            View.SYSTEM_UI_FLAG_LOW_PROFILE or
                    View.SYSTEM_UI_FLAG_FULLSCREEN or
                    View.SYSTEM_UI_FLAG_LAYOUT_STABLE or
                    View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY or
                    View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION or
                    View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
        activity?.window?.decorView?.systemUiVisibility = flags
        (activity as? AppCompatActivity)?.supportActionBar?.hide()
    }
    private val showPart2Runnable = Runnable {
        // Delayed display of UI elements
        fullscreenContentControls?.visibility = View.VISIBLE
    }
    private var visible: Boolean = false
    private val hideRunnable = Runnable { hide() }
    /**
     * Touch listener to use for in-layout UI controls to delay hiding the
     * system UI. This is to prevent the jarring behavior of controls going away
     * while interacting with activity UI.
     */
    private val delayHideTouchListener = View.OnTouchListener { _, _ ->
        if (AUTO_HIDE) {
            delayedHide(AUTO_HIDE_DELAY_MILLIS)
        }
        false
    }

    private var dummyButton: Button? = null
    private var fullscreenContent: View? = null
    private var fullscreenContentControls: View? = null

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        return inflater.inflate(R.layout.fragment_fullscreen, container, false)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        visible = true

        dummyButton = view.findViewById(R.id.dummy_button)
        fullscreenContent = view.findViewById(R.id.fullscreen_content)
        fullscreenContentControls = view.findViewById(R.id.fullscreen_content_controls)
        // Set up the user interaction to manually show or hide the system UI.
        fullscreenContent?.setOnClickListener { toggle() }

        // Upon interacting with UI controls, delay any scheduled hide()
        // operations to prevent the jarring behavior of controls going away
        // while interacting with the UI.
        dummyButton?.setOnTouchListener(delayHideTouchListener)
    }

    override fun onResume() {
        super.onResume()
        activity?.window?.addFlags(WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS)

        // Trigger the initial hide() shortly after the activity has been
        // created, to briefly hint to the user that UI controls
        // are available.
        delayedHide(100)
    }

    override fun onPause() {
        super.onPause()
        activity?.window?.clearFlags(WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS)

        // Clear the systemUiVisibility flag
        activity?.window?.decorView?.systemUiVisibility = 0
        show()
    }

    override fun onDestroy() {
        super.onDestroy()
        dummyButton = null
        fullscreenContent = null
        fullscreenContentControls = null
    }

    private fun toggle() {
        if (visible) {
            hide()
        } else {
            show()
        }
    }

    private fun hide() {
        // Hide UI first
        fullscreenContentControls?.visibility = View.GONE
        visible = false

        // Schedule a runnable to remove the status and navigation bar after a delay
        hideHandler.removeCallbacks(showPart2Runnable)
        hideHandler.postDelayed(hidePart2Runnable, UI_ANIMATION_DELAY.toLong())
    }

    @Suppress("InlinedApi")
    private fun show() {
        // Show the system bar
        fullscreenContent?.systemUiVisibility =
            View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN or
                    View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
        visible = true

        // Schedule a runnable to display UI elements after a delay
        hideHandler.removeCallbacks(hidePart2Runnable)
        hideHandler.postDelayed(showPart2Runnable, UI_ANIMATION_DELAY.toLong())
        (activity as? AppCompatActivity)?.supportActionBar?.show()
    }

    /**
     * Schedules a call to hide() in [delayMillis], canceling any
     * previously scheduled calls.
     */
    private fun delayedHide(delayMillis: Int) {
        hideHandler.removeCallbacks(hideRunnable)
        hideHandler.postDelayed(hideRunnable, delayMillis.toLong())
    }

    companion object {
        /**
         * Whether or not the system UI should be auto-hidden after
         * [AUTO_HIDE_DELAY_MILLIS] milliseconds.
         */
        private const val AUTO_HIDE = true

        /**
         * If [AUTO_HIDE] is set, the number of milliseconds to wait after
         * user interaction before hiding the system UI.
         */
        private const val AUTO_HIDE_DELAY_MILLIS = 3000

        /**
         * Some older devices needs a small delay between UI widget updates
         * and a change of the status and navigation bar.
         */
        private const val UI_ANIMATION_DELAY = 300
    }
}

Answer 1

根据这个 BottomNavigationView 问题帖子:

https://github.com/material-components/material-components-android/issues/499#issuecomment-519618931

bottomNavigationView.setOnApplyWindowInsetsListener(null);

上面的代码示例可能会解决这个问题。