我的actionBar没有出现

Question

I have been having trouble with my action bars, I got it set up on my xml front end like this:

<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar4"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/colorPrimary"
    android:label="@string/dadosCadastrais"
    android:minHeight="?attr/actionBarSize"
    android:theme="?attr/actionBarTheme" />

And on the Java activity:

Toolbar toolbar = findViewById(R.id.toolbar4);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setDisplayShowHomeEnabled(true);

I have already tried changing the theme the app uses, the theme the layout uses and even the activities theme to allow/forbid a toolbar to show up. Even though my java class extends AppCompatActivity it does not show!

PS: Got it working now! The problem was the setup on java code itself, there was an hidden method which was overwritting my setup, thx for the help!

Answer 1

Make sure your activity inflates the correct layout containing your ToolBar.

protected void setContentView() {
    setContentView(R.layout.your_activity_layout);
}

Your activity layout should contain your ToolBar. Here is a code example:

<?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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:keepScreenOn="true"
    android:orientation="vertical">

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

    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/frameLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"></FrameLayout>

</LinearLayout>