Android Home button on Action Bar Does Not Appear -

i came across strange problem home button on toolbar not showing.

activity_main.xml

    <?xml version="1.0" encoding="utf-8"?>  <android.support.v4.widget.drawerlayout     xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     xmlns:app="http://schemas.android.com/apk/res-auto"     android:id="@+id/drawer_layout"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:elevation="@dimen/design_navigation_elevation"     android:fitssystemwindows="true"     tools:context="my.app.mainactivity">      <android.support.design.widget.coordinatorlayout         android:layout_width="match_parent"         android:layout_height="match_parent">          <include layout="@layout/toolbar"/>         <include layout="@layout/content_main"/>         <include layout="@layout/fab"/>      </android.support.design.widget.coordinatorlayout>      <android.support.design.widget.navigationview         android:id="@+id/navigation_drawer"         android:layout_width="wrap_content"         android:layout_height="match_parent"         android:layout_gravity="start"         app:headerlayout="@layout/navigation_drawer_header"         app:menu="@menu/menu_navigation_drawer"/>  </android.support.v4.widget.drawerlayout> 

toolbar.xml

    <?xml version="1.0" encoding="utf-8"?> <android.support.design.widget.appbarlayout     xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     android:layout_height="wrap_content"     android:layout_width="match_parent"     android:theme="@style/apptheme.appbaroverlay">      <android.support.v7.widget.toolbar         android:id="@+id/toolbar"         android:layout_width="match_parent"         android:layout_height="?attr/actionbarsize"         android:background="?attr/colorprimary"         app:popuptheme="@style/apptheme.popupoverlay" />  </android.support.design.widget.appbarlayout> 

mainactivity.java

public class mainactivity extends appcompatactivity {  private 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().setdisplayshowhomeenabled(true); 

i have app using same method, working fine. idea?

you have :

<android.support.design.widget.navigationview         android:id="@+id/navigation_drawer"         android:layout_width="wrap_content"         android:layout_height="match_parent"         android:layout_gravity="start"         app:headerlayout="@layout/navigation_drawer_header"         app:menu="@menu/menu_navigation_drawer"/> 

which has default icon:

and take @ blog: codetheory.in (web.archive)

which says:

sethomebuttonenabled(boolean enabled)

this method similar previous one(setdisplayhomeasupenabled(boolean showhomeasup)) actually, except left-facing caret doesn’t show unless android:parentactivityname specified.

instead, try use:

getsupportactionbar().setdisplayhomeasupenabl‌​‌​ed(true); 

then, it should work without drawer guess.because has default icon.

check results without drawer suggested code:

somehow, don't need that.