onBackpressed() method keeping me awake all night

Question

I can not navigate from page B to page A using onBackpressed() (hardware button) its just exit the whole program. :( been trying different codes for 7 days and nights now. Please can someone help the newby.

I have declared the parent activity name inside Manifest file

        <activity android:name="lk.ceesl.engteachersl.Nounintro"
          android:parentActivityName="lk.ceesl.engteachersl.MainActivity">

        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value="lk.ceesl.engteachersl.MainActivity" />

        </activity>

Then I wrote the codes in MainActivity.java to override the onBackpressed() method

@Override
public void onBackPressed() {

  moveTaskToBack(true);

}

now its just closes the app and runs in the background when i press hardware back button. please give me a solution for the most essential part of my app which is navigating with HW back button (NOT action bar backbutton please). thank you so so much in advance.

Answer 1

I have create a sample project for you . Just to navigate through one activity to another .

MainActivity

public class MainActivity extends AppCompatActivity {

    Button button;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button = (Button) findViewById(R.id.button);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this,SecondActivity.class);
                startActivity(intent);
            }
        });
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.surroundapps.backbutton.MainActivity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Go to Second Activity"
        android:id="@+id/button"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"/>
</RelativeLayout>

SecondActivity.java

public class SecondActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);
    }
}

activity_second.xml

public class SecondActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.shuvro.backbutton">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>

                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
        <activity android:name=".SecondActivity">
        </activity>
    </application>

</manifest>

Hope it will help you to understand how to navigate through activity