android - How to add image in toolbar

Question

I am following this example to create my app now i am trying to add image in my toolbar the but image is not displaying,i am trying to set my app logo,following is my code and toolbar xml can any one tell me what is mistake?

toolbar.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:local="http://schemas.android.com/apk/res-auto"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:minHeight="?attr/actionBarSize"
    android:background="?attr/colorPrimary"
    local:theme="@style/MyMaterialTheme.Base"
    local:popupTheme="@style/ThemeOverlay.AppCompat.Light" >

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/toolbartitle"
        />

    </android.support.v7.widget.Toolbar>

MainActivity.java

public class MainActivity extends AppCompatActivity implements FragmentDrawer.FragmentDrawerListener {

    private static String TAG = MainActivity.class.getSimpleName();

    private Toolbar mToolbar;
    private FragmentDrawer drawerFragment;
    private String chng;
    private Intent i;
    public SearchView searchView;
    public SearchManager searchManager;

    // Alert Dialog Manager
    AlertDialogManager alert = new AlertDialogManager();

    // Session Manager Class
    SessionManager session;

    private String id;
    private boolean b;
    private String rasa;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        session = new SessionManager(getApplicationContext());
        id = getIntent().getStringExtra("id");
        System.out.println("MAIN ID : " + id);
       /* i=getIntent();
        chng=i.getStringExtra("Changes");*/

      //  Toast.makeText(getApplicationContext(),chng,Toast.LENGTH_LONG).show();
       mToolbar = (Toolbar) findViewById(R.id.toolbar);

        setSupportActionBar(mToolbar);
       getSupportActionBar().setDisplayShowHomeEnabled(false);
        getSupportActionBar().setDisplayShowTitleEnabled(false);

        drawerFragment = (FragmentDrawer)
                getSupportFragmentManager().findFragmentById(R.id.fragment_navigation_drawer);
        drawerFragment.setUp(R.id.fragment_navigation_drawer, (DrawerLayout) findViewById(R.id.drawerLayout),mToolbar);
        drawerFragment.setDrawerListener(this);
        displayView(0);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

This how my toolbar shows right now

Answer 1

  <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="@color/color_blue"
            app:popupTheme="@style/AppTheme.PopupOverlay">

            <ImageView
                android:id="@+id/tv_header_title"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center"
                android:src="@mipmap/header_title" />
        </android.support.v7.widget.Toolbar>

You can set Event of button also by this method...

 public static void showToolBar(Toolbar toolbar,
                                   final AppCompatActivity activity) {
        activity.setSupportActionBar(toolbar);
        activity.getSupportActionBar().setDisplayShowTitleEnabled(false);
        @SuppressWarnings("deprecation")
        Drawable drawable = activity.getResources().getDrawable(
                R.mipmap.back_icon);
        drawable.setColorFilter(
                activity.getResources().getColor(R.color.color_white),
                android.graphics.PorterDuff.Mode.SRC_ATOP);
        activity.getSupportActionBar().setHomeAsUpIndicator(drawable);
        toolbar.setBackgroundColor(activity.getResources().getColor(
                R.color.color_blue));
        activity.getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                activity.finish();
            }
        });
    }