Ao arrastar o FloatingActionButton, além dele não aparecer no meu layout, recebo os seguintes warnings:
AdapterViews cannot have children in XML
A list/grid should have no children declared in XML AdapterViews such as ListViews must be configured with data from Java code, such as a ListAdapter. Issue id: AdapterViewChildren http://developer.android.com/reference/android/widget/AdapterView.html
Keyboard inaccessible widget
clickable' attribute found, please also add 'focusable' A widget that is declared to be clickable but not declared to be focusable is not accessible via the keyboard. Please add the focusable attribute as well.
Issue id: KeyboardInaccessibleWidget
Suggested Fix
Set focusable = "true"
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Segue o código da activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:id="@+id/activity_main_lista_de_alunos"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/floatingActionButton3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:clickable="true"
app:srcCompat="@mipmap/ic_launcher" />
</ListView>
</LinearLayout>Estou utilizando a versão 3.5.1 do Android Studio no Linux/Ubuntu.
