Switch between Fragments with onNavigationItemSelected in new Navigation Drawer Activity template (Android Studio 1.4 onward)

So, based on @L.L.'s answer I was able to solve this problem.

First of all, add your FrameLayout to your content_main.xml file:

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

In your MainActivity (or whatever you have named the Activity with the navigation drawer) define a method named displayView

 public void displayView(int viewId) {

    Fragment fragment = null;
    String title = getString(R.string.app_name);

    switch (viewId) {
        case R.id.nav_news:
            fragment = new NewsFragment();
            title  = "News";

            break;
        case R.id.nav_events:
            fragment = new EventsFragment();
            title = "Events";
            break;

    }

    if (fragment != null) {
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        ft.replace(R.id.content_frame, fragment);
        ft.commit();
    }

    // set the toolbar title
    if (getSupportActionBar() != null) {
        getSupportActionBar().setTitle(title);
    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);

}

Am switching between 3 custom Fragments; NewsFragment, EventsFragment and GalleryFragment.

in my menu activity_main_drawer I have changed the content to this:

<menu xmlns:android="http://schemas.android.com/apk/res/android">

<group android:checkableBehavior="single">
    <item android:id="@+id/nav_news"  
        android:icon="@android:drawable/ic_menu_news"
        android:title="News" />
    <item android:id="@+id/nav_events" 
        android:icon="@android:drawable/ic_menu_events"
        android:title="Events" />
    <item android:id="@+id/nav_gallery" 
        android:icon="@android:drawable/ic_menu_gallery"
        android:title="Gallery" />
  </group>
</menu>

Going back to the Activity class, in your onNavigationItemSelected method do this:

@Override
public boolean onNavigationItemSelected(MenuItem item) {
    displayView(item.getItemId());
    return true;
}

Finally, the last statement in your onCreate method:

 @Override
protected void onCreate(Bundle savedInstanceState) {
    ....
    ....
    displayView(R.id.nav_news);
}

This is because I want the first view my user sees to be News.Change it to whatever you choose.

Handle back press event:

As it stands, if you press the back button from any of the Fragments, the app exits.I want my app to go back to the News Fragment (my home fragment) when the user presses the back button. So I did this:

Declared a boolean variable:

private boolean viewIsAtHome;

then in the displayView() method I did this:

 public void displayView(int viewId){
    Fragment fragment = null;
    String title = getString(R.string.app_name);

    switch (viewId) {
        case R.id.nav_news:
            fragment = new NewsFragment();
            title  = getString(R.string.news_title);
            viewIsAtHome = true;

            break;
        case R.id.nav_events:
            fragment = new EventsFragment();
            title = getString(R.string.events_title);
            viewIsAtHome = false;
            break;

        case R.id.nav_gallery:
            fragment = new GalleryFragment();
            title = getString(R.string.gallery_title);
            viewIsAtHome = false;
            break;

Finally, delete your old onBackPressed method and create a new one like this outside the onCreate() method:

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    }
    if (!viewIsAtHome) { //if the current view is not the News fragment
        displayView(R.id.nav_news); //display the News fragment
    } else {
        moveTaskToBack(true);  //If view is in News fragment, exit application
    }
}

Works for me.


You should not change the DrawerLayout, you only need to add a frame in the "content_main.xml".

Follow the steps below:

  1. open the "content_main.xml" file located in the "layout" folder.

  2. use the code below:

    <?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior" tools:showIn="@layout/app_bar_main"
    tools:context=".MainActivity">    
    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent" android:id="@+id/mainFrame">
    </FrameLayout>   
</RelativeLayout>

  3. go to the onNavigationItemSelected method:

    public boolean onNavigationItemSelected(MenuItem item) {
  int id = item.getItemId();
  Fragment fragment;

if (id == R.id.nav_camara) {
    fragment = new YourFragment();
    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    ft.replace(R.id.mainFrame, fragment);
    ft.commit();
}
else if (id == R.id.nav_gallery) {

}
else if (id == R.id.nav_slideshow) {

}
else if (id == R.id.nav_manage) {

} else if (id == R.id.nav_share) {

} else if (id == R.id.nav_send) {

}

DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}

another way is:

public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    Fragment fragment;
    int id = item.getItemId();

    if (id == R.id.nav_camera) {
        // Handle the camera action
        fragment = new BlankFragment();
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        ft.replace(R.id.container_new, fragment);
        ft.commit();
    } else if (id == R.id.nav_gallery) {
        fragment = new HorizontalView();
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        ft.replace(R.id.container_new,fragment);
        ft.commit();
    } else if (id == R.id.nav_slideshow) {
        fragment = new FragmentVerticleView();
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        ft.replace(R.id.container_new,fragment);
        ft.commit();

    } else if (id == R.id.nav_manage) {

    } else if (id == R.id.nav_share) {

    } else if (id == R.id.nav_send) {

    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

And then you'll need to implemts all the fragments to your activity. In my case it's

MainActivity.java

    public class MainActivity extends AppCompatActivity
    implements BlankFragment.OnFragmentInteractionListener, HorizontalView.OnFragmentInteractionListener,FragmentVerticleView.OnFragmentInteractionListener,OnNavigationItemSelectedListener
     { 
    //coding stuff
    }

And to handle the Exception that is Thrown in fragment java file

    "must implement OnFragmentInteractionListener"

you simply add below method

      public void    onFragmentInteraction(Uri uri){
    //We can keep this empty
}

And there you go! All set

Thanks to this Tutorial to strike this

Tags:

Android

Navigation Drawer

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