so I have a layout like this Layout and I want to access the fab logout on header layout when the drawer is opened in main activity. Is there anyway to do that? thank you so much

Below are my layout and code

main activity xml

 <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <androidx.viewpager2.widget.ViewPager2
            android:id="@ id/viewPagerMain"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent">

        </androidx.viewpager2.widget.ViewPager2>

        <com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@ id/bottomNav"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            app:labelVisibilityMode="labeled"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:menu="@menu/bottom_nav" />
    </androidx.constraintlayout.widget.ConstraintLayout>


</androidx.coordinatorlayout.widget.CoordinatorLayout>

drawer layout xml

<androidx.drawerlayout.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@ id/drawerLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <include
        layout="@layout/activity_main"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <com.google.android.material.navigation.NavigationView
        android:id="@ id/navView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        app:headerLayout="@layout/nav_header_main"
        app:menu="@menu/nav_bar" />
</androidx.drawerlayout.widget.DrawerLayout>

header layout xml

    <ImageView
        android:id="@ id/imgBG"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:adjustViewBounds="true"
        android:scaleType="centerCrop"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:srcCompat="@tools:sample/backgrounds/scenic" />

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@ id/fabLogOut"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="32dp"
        android:clickable="true"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:srcCompat="@drawable/ic_baseline_login_24"
        app:tint="@color/white" />

    <androidx.cardview.widget.CardView
        android:id="@ id/cardView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="48dp"
        app:cardCornerRadius="100dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@ id/fabLogOut">

        <ImageView
            android:id="@ id/imgProfile"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            tools:srcCompat="@tools:sample/avatars" />
    </androidx.cardview.widget.CardView>

    <TextView
        android:id="@ id/txtFullName"
        style="@style/body"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="48dp"
        android:layout_marginTop="16dp"
        android:text="TextView"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@ id/cardView" />

    <TextView
        android:id="@ id/txtUsernameHeader"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="48dp"
        android:layout_marginBottom="16dp"
        android:text="TextView"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@ id/txtFullName" />

</androidx.constraintlayout.widget.ConstraintLayout>

and this is my mainactivity.kt code

class MainActivity : AppCompatActivity() {
    val fragments:ArrayList<Fragment> = ArrayList()

    override fun onCreate(savedInstanceState: Bundle?) {
        var sharedUname = "com.austin.dailymemedigest"
        var shared = getSharedPreferences(sharedUname, Context.MODE_PRIVATE)
        var username =  shared.getString(LoginActivity.SHARED_USERNAME, null)

        super.onCreate(savedInstanceState)
        setContentView(R.layout.drawer_layout)
        setSupportActionBar(toolbar)
        supportActionBar?.title="Daily Meme Digest"
        supportActionBar?.setDisplayHomeAsUpEnabled(false)
        var drawerToggle =
            ActionBarDrawerToggle(this, drawerLayout, toolbar,R.string.app_name,
                R.string.app_name)
        drawerToggle.isDrawerIndicatorEnabled = true
        drawerToggle.syncState()

        fragments.add(HomeFragment())
        fragments.add(SelfCreationFragment())
        fragments.add(LeaderboardFragment())

        val adapter = MyViewPagerAdapter(this, fragments)

        viewPagerMain.adapter = adapter

        viewPagerMain.registerOnPageChangeCallback(
            object : ViewPager2.OnPageChangeCallback(){
                override fun onPageSelected(position: Int) {
                    val itemId = bottomNav.menu.getItem(position).itemId
                    bottomNav.selectedItemId = itemId
                }
            }
        )

        bottomNav.setOnItemSelectedListener{
            if(it.itemId == R.id.ItemHomeBot){
                viewPagerMain.currentItem = 0
            } else if(it.itemId == R.id.ItemMyCreationBot){
                viewPagerMain.currentItem = 1
            } else if (it.itemId == R.id.ItemLeaderboardBot){
                viewPagerMain.currentItem = 2
            } else{
                viewPagerMain.currentItem = 3
            }
            true
        }

        val fab = findViewById<View>(R.id.fabLogOut) as? FloatingActionButton
        fab?.setOnClickListener {
            Toast.makeText(this, "hahahah", Toast.LENGTH_SHORT).show()
        }
    }
}

i tried this code line in the mainactivity.kt but the toast didn't show up

val fab = findViewById<View>(R.id.fabLogOut) as? FloatingActionButton
        fab?.setOnClickListener {
            Toast.makeText(this, "hahahah", Toast.LENGTH_SHORT).show()
        }

CodePudding user response：

Try accessing fabLogOut like below with referring to headerview like this,

val navView: NavigationView = findViewById(R.id.navView)
       
val headerView: View = navView.getHeaderView(0)

val fab = headerView.findViewById<View>(R.id.fabLogOut) as? FloatingActionButton

fab?.setOnClickListener {
      Toast.makeText(this, "hahahah", Toast.LENGTH_SHORT).show()
 }