How to show Admob interstitial in extends Activity

Question

I˙m learning android development, so I buy source code and I`m trying to change UI and other elements. With UI I was not having any problems but in final stage when I want to ad Admob interstitial ads I have a problem. I want to show interstitial when user click on one of list items but this is not a problem. I dont know how to integarate Admob interstitials in Adapter.java file, this is begining of code of that file.

public class RingtonesActivity extends Activity {

private ListView listView;
private ListRingtonesAdapter adapter;
private ArrayList<SongInfo> listSong = new ArrayList<SongInfo>();
private Util util = new Util();
private ProgressBar progressBarParent;
private LinearLayout linearLayout_contentProgress;

private static final int PREFERENCES = Menu.FIRST;
private static final int QUIT = Menu.FIRST + 1;


/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.ringtonelist);
    listView = (ListView) findViewById(R.id.list);
    progressBarParent = (ProgressBar)findViewById(R.id.progressBarParent);
    Resources res = getResources();
    progressBarParent.setProgressDrawable(res.getDrawable(R.drawable.progressbarstyle));
    linearLayout_contentProgress = (LinearLayout)findViewById(R.id.LL_contentProgressBarParent);
    refreshList();

}

public static class Admob extends Activity {
    InterstitialAd mInterstitialAd;

    public void onCreate() {
        mInterstitialAd = new InterstitialAd(this);
        mInterstitialAd.setAdUnitId("ca-app-pub-3940256099942544/1033173712");
        requestNewInterstitial();
        if (mInterstitialAd.isLoaded()) {
            mInterstitialAd.show();
        }
    };

    public void requestNewInterstitial() {
        AdRequest adRequest = new AdRequest.Builder()
                  .addTestDevice("YOUR_DEVICE_HASH")
                  .build();

        mInterstitialAd.loadAd(adRequest);
    }

}

There is no onCreate method to include Admob code, and when I˙m trying to create onCreate method and adding admob code I got errors.

Guys, any help is very very welcome! :) Thanks, Anna

After I use suggestion from @SafwanHijazi I got this error

FATAL EXCEPTION: main
Process: ringtones.codebhak, PID: 20938
java.lang.NullPointerException
at  ringtones.codebhak.RingtonesActivity.nativeDisplayAd(RingtonesActivity.java:73)
at ringtones.codebhak.ListRingtonesAdapter.getView(ListRingtonesAdapter.java:175)
at android.widget.AbsListView.obtainView(AbsListView.java:2715)
at android.widget.ListView.makeAndAddView(ListView.java:1801)
at android.widget.ListView.fillDown(ListView.java:697)
at android.widget.ListView.fillFromTop(ListView.java:763)
at android.widget.ListView.layoutChildren(ListView.java:1627)
at android.widget.AbsListView.onLayout(AbsListView.java:2528)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1677)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1531)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1440)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1677)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1531)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1440)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1677)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1531)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1440)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1677)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1531)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1440)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1677)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1531)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1440)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
at android.view.View.layout(View.java:15655)
at android.view.ViewGroup.layout(ViewGroup.java:4856)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2284)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2004)
at android.view.ViewRootImpl.doTrave

Answer 1

try something like this:

import android.app.Activity;
import android.os.Bundle;

import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.InterstitialAd;

public class MyActivity extends Activity {
    private InterstitialAd interstitial;
    private boolean loaded = false;
    private static MyActivity appActivity;
    AdRequest adRequest;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        appActivity = this;
        createAdmob();
    }

    private void createAdmob() {
        // Create the interstitial.
        interstitial = new InterstitialAd(this);
        interstitial.setAdUnitId("YOUR UNIT ID");

        // Create ad request.
        adRequest = new AdRequest.Builder().build();

        // Begin loading your interstitial.
        interstitial.loadAd(adRequest);
        loaded = true;

    }

    public static void nativeDisplayAd() {

        appActivity.displayAd();
    }

    public void displayAd() {
        // Just to load ad before display as required from admob sdk.
        if (loaded) {
            displayInterstitial();
            loaded = false;
        } else {
           // or only load new ad.
            createAdmob();
        }
    }
    // Invoke displayInterstitial() when you are ready to display ad
    // interstitial.
    public void displayInterstitial() {
        if (interstitial.isLoaded()) {
            interstitial.show();
        }
    }
}

From your adapter call static method (nativeDisplayAd), but take care that ads displayed after loaded.