MotionLayout 中的浮动操作按钮 (FAB)，.show() 不起作用，.hide() 不正确

Question

我有带有 FragmentContainerView、BottomNavigationView 和 FAB 的 MainActivity。

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.motion.widget.MotionLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/motionLayoutActivityMain"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layoutDescription="@xml/activity_main_scene"
    tools:context=".ui.MainActivity">


    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/fragmentContainer"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@+id/bottomNavigation"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent">

    </androidx.fragment.app.FragmentContainerView>

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottomNavigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:labelVisibilityMode="selected"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:menu="@menu/bottom_navigation_menu" />

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/verticalGuidelineActivityMain"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintGuide_percent="0.8" />

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/filterFabActivityMain"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginBottom="72dp"
        android:contentDescription="fab"
        android:src="@android:drawable/ic_menu_add"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toRightOf="@id/verticalGuidelineActivityMain" />

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/horizontalGuidelineActivityMain"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="1"
        app:layout_constraintStart_toStartOf="parent" />

</androidx.constraintlayout.motion.widget.MotionLayout>

当我点击名为 fab.show() 的 BottomNavifationView 的 item1 或 item2 时，如果我点击名为 fab.hide() 的 item3。

MainActivity.kt:

//SOME CODE BEFORE

binding.bottomNavigation.setOnNavigationItemSelectedListener { item ->
            when (item.itemId) {
                R.id.membersFragment -> {
                    fragmentManager.beginTransaction().hide(activeFragment).show(membersFragment).commit()
                    activeFragment = membersFragment

                    // Show fab when select membersFragment
                    binding.filterFabActivityMain.show()

                    true
                }
                R.id.teamsFragment -> {
                    fragmentManager.beginTransaction().hide(activeFragment).show(teamsFragment).commit()
                    activeFragment = teamsFragment

                    // Show fab when select teamsFragment
                    binding.filterFabActivityMain.show()

                    true
                }
                R.id.aboutFragment -> {
                    fragmentManager.beginTransaction().hide(activeFragment).show(aboutFragment).commit()
                    activeFragment = aboutFragment

                    // Hide fab when select aboutFragment
                    binding.filterFabActivityMain.hide()

                    true
                }
                else -> false
            }
        }

//SOME CODE AFTER

fab.hide() 隐藏 FAB，但如果我点击 FAB 位置 fab.clickListener 将被调用。

fab.show() 不会显示 FAB。

Answer 1

MotionLayout 控制场景，所以需要使用app:visibilityMode="ignore" 对运动场景中FAB 的约束

<Constraint
android:id="@+id/filterFabActivityMain"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginBottom="72dp"
android:contentDescription="fab"
android:src="@android:drawable/ic_menu_add"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toRightOf="@id/verticalGuidelineActivityMain"
app:visibilityMode="ignore" />

MotionLayout 中的浮动操作按钮 (FAB)，.show() 不起作用，.hide() 不正确

Floating action button(FAB) in MotionLayout, .show() doesn't work, .hide() work incorrect

android

kotlin

floating-action-button

bottomnavigationview

material-components-android