在Android的所有屏幕上都可以看到Extra Back Button

Question

1)How do I delete the extra black arrow button? It shows in all pages. But the white arrow button is only in active state. When white button is pressed, it can go back.

2)How can I set the action bar with back button comes first followed with the title?

Answer 1

ActionBar actionBar= getSupportActionBar(); actionBar.setDisplayHomeAsUpEnabled(false); try putting this at top inside your onCreate method,this will disable the default toolbar button of the app,then you can create your own toolbar and add it,but thats a whole other process,this answer would simply hide your icon and title which is coming automatically

Answer 2

I have enclosed my code..

MainActivity.java

public class MainActivity extends AppCompatActivity implements View.OnClickListener {     
        Toolbar toolbar;
                @Override
                    protected void onCreate(Bundle savedInstanceState) {
                        super.onCreate(savedInstanceState);
                        setContentView(R.layout.activity_main);
                        toolbar = (Toolbar) findViewById(R.id.toolbar);
                        setSupportActionBar(toolbar);
                        getSupportActionBar().setTitle("");
                        getSupportActionBar().setDisplayShowTitleEnabled(true);
                        getSupportActionBar().setDisplayHomeAsUpEnabled(false);
                        getSupportActionBar().setDefaultDisplayHomeAsUpEnabled(false);
                }

                    public void showFragment(Fragment fragment, String back_stack_name, boolean isAddToBackStack) {
                        FragmentTransaction transaction = getFragmentManager().beginTransaction();
                        transaction.add(R.id.container, fragment);
                        if (isAddToBackStack) {
                            transaction.addToBackStack(back_stack_name);
                        }
                        transaction.commit();
                    }

                    @Override
                    public void onBackPressed() {
                        if (getFragmentManager().getBackStackEntryCount() == 0) {
                            showAlertDialog(Constants.EXIT_APP, Constants.APP_NAME);
                        } else {
                            getFragmentManager().popBackStackImmediate();
                        }
                    }
    }

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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <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="?attr/colorPrimary"
            android:fitsSystemWindows="true"
            app:popupTheme="@style/AppTheme.PopupOverlay">

            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:src="@drawable/back_white"
                android:visibility="gone"
                android:id="@+id/back_btn"
                android:contentDescription="Back" />
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center"
                android:textColor="@color/white"
                android:textSize="@dimen/textSize_17sp"
                android:id="@+id/title_toolbar_txt"
                android:visibility="gone"/>
        </android.support.v7.widget.Toolbar>

        <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:showIn="@layout/app_bar_main">

        <FrameLayout
            android:id="@+id/container"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>


    </RelativeLayout>

    </LinearLayout>

</LinearLayout>