Material Design

// - res/values/styles.xml

// ...
 <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
// ...

<androidx.appcompat.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="@color/design_default_color_primary"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
        app:popupTheme="@style/Theme.AppCompat.Light"
        tools:ignore="MissingConstraints" />

onCreate() {
		// ...
		setSupportActionBar(toolbar)
}

override fun onCreateOptionsMenu(menu: Menu?): Boolean {
    menuInflater.inflate(R.menu.toolbar, menu)
    return true
}

override fun onOptionsItemSelected(item: MenuItem): Boolean {
    when (item.itemId) {
       R.id.backup -> Toast.makeText(this, "backup", Toast.LENGTH_LONG).show()
	     R.id.delete -> Toast.makeText(this, "delete", Toast.LENGTH_LONG).show()
       R.id.setting -> Toast.makeText(this, "setting", Toast.LENGTH_LONG).show()
		}
    return true
}

<?xml version="1.0" encoding="utf-8"?>
<menu
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/backup"
        android:icon="@drawable/ic_backup"
        android:title="Backup"
        app:showAsAction="always" />
    <item
        android:id="@+id/delete"
        android:icon="@drawable/ic_delete"
        android:title="Delete"
        app:showAsAction="ifRoom" />
    <item
        android:id="@+id/setting"
        android:icon="@drawable/ic_setting"
        android:title="Setting"
        app:showAsAction="never" />
</menu>

<?xml version="1.0" encoding="utf-8"?>
<androidx.drawerlayout.widget.DrawerLayout
// ...

<com.google.android.material.navigation.NavigationView
        android:id="@+id/navView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:menu="@menu/nav_menu" // 菜单项
        app:headerLayout="@layout/nav_header"/> // 头部