Drawer menu hamburger button doesn`t work on create

Question

So, the problem is that my hamburger button does not work when the application is started - it toggles, but the drawer menu doesn`t open. When I open and close the drawer menu by swiping from the side, it starts working... and so every time any new activity is started.

This is my kotlin code:

open class BaseActivity : AppCompatActivity(), Observer, NavigationView.OnNavigationItemSelectedListener {

private var drawer: DrawerLayout? = null

fun oncreate() {


    val toolbar: android.support.v7.widget.Toolbar = this.findViewById(R.id.toolbar)

    setSupportActionBar(toolbar)
    val actionBar = this.supportActionBar
    if (actionBar != null) {
        actionBar.setDisplayHomeAsUpEnabled(true)
        actionBar.setHomeButtonEnabled(true)
    }
    //val actionbar: ActionBar? = supportActionBar
    drawer = findViewById(R.id.drawer_layout)
    val navigationView: NavigationView = findViewById(R.id.nav_view)
    navigationView.setNavigationItemSelectedListener(this)

    toggle = ActionBarDrawerToggle(
        this, drawer, toolbar,
        R.string.navigation_drawer_open, R.string.navigation_drawer_close
    )
    actionBar?.apply {
        setDisplayHomeAsUpEnabled(true)
        setHomeAsUpIndicator(R.drawable.ic_menu)
    }

    drawer!!.addDrawerListener(toggle)
    toggle.syncState()

}

override fun onOptionsItemSelected(item: MenuItem): Boolean {
    return when (item.itemId) {

        android.R.id.home -> {
            drawer!!.openDrawer(GravityCompat.START)
            true
        }
        else -> super.onOptionsItemSelected(item)
    }
}

override fun onNavigationItemSelected(item: MenuItem): Boolean {
    when (item.itemId) {
        android.R.id.home -> {
            drawer!!.openDrawer(GravityCompat.START)
            true
        }
        //other items
    }
    drawer!!.closeDrawer(GravityCompat.START)
    return true
}

And the xml code:

    <?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/drawer_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        android:background="@drawable/background"
        tools:openDrawer="start" android:visibility="visible">

    <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

        <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="@color/colorPrimary"
                android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
                android:visibility="visible"/>

//more elements here

    </LinearLayout>

    <android.support.design.widget.NavigationView
            android:id="@+id/nav_view"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_gravity="start"
            app:headerLayout="@layout/nav_header"
            app:itemTextAppearance="@style/txt_expandable"
            app:menu="@menu/drawer_menu" android:visibility="gone">
    </android.support.design.widget.NavigationView>

</android.support.v4.widget.DrawerLayout>

I`ve tried a lot of things to solve the problem, but nothing seems to work... I followed exactly the steps in the Kotlin documentation and everything, but the problem stays.

Answer 1

Here is error:

app:menu="@menu/drawer_menu" android:visibility="gone">

Remove android:visibility="gone". Should be:

app:menu="@menu/drawer_menu">