Kotlin Android Google AdMob Interstitial Ads Example

In this tutorial, we implement the Google AdMob Interstitial Ads in our Android application. To place the Google AdMob in Android application, we need to create the Google Ad Unit Id. The complete reference for creating the Google AdMod account and generate the Ad Unit Id is described at Android Google AdMob.

An Interstitials ad is the full-screen ad that covers the entire activity layout. This ad is displayed at a transition point of an activity. To implement the Google AdMob in the Android application, choose Google AdMob Ads Activity and select the Ad format type as Interstitials.

We are also able to place the Google AdMob Ads on other activities such as Blank Activity.

Add the Google ads dependency 'com.google.android.gms:play-services-ads:17.0.0' in the build.gradle file:

build.gradle

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.google.android.gms:play-services-ads:17.0.0'
    testImplementation 'junit:junit:4.12'
}

activity_main.xml

Add your UI code in the activity_main.xml. The Button component is used to load the ad.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="example.javatpoint.com.kotlininterstitialads.MainActivity">

    <!-- view for AdMob Interstitial Ad -->
    <TextView
        android:id="@+id/app_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="50dp"
        android:text="@string/interstitial_ad_sample"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <Button
        android:id="@+id/load_ad_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="@string/load_ad" />
</RelativeLayout>

strings.xml

Add the created ad unit id in the string.xml file.

<resources>
    <string name="app_name">KotlinInterstitialAds</string>
    <string name="action_settings">Settings</string>
    <string name="interstitial_ad_sample">Interstitial Ad Sample</string>
    <string name="load_ad">Load Ad</string>
    <!-- -
        This is an ad unit ID for an interstitial test ad. Replace with your own interstitial ad unit id.
    -->
    <string name="interstitial_ad_unit_id">ca-app-pub-3940256099942544/1033173712</string>
</resources>

MainActivity.kt

Add the following code in MainActivity.kt class. To load the ad on the UI, create the instance of InterstitialAd and initialize the ad unit id on InterstitialAd interstitialAd.adUnitId = getString(R.string.interstitial_ad_unit_id).

Override the InterstitialAd listeners onAdLoaded(), onAdFailedToLoad(), onAdClosed. To load the ad on clicking the button, create the instance of AdRequest and load the ad by calling InterstitialAd!!.loadAd(AdRequest).

package example.javatpoint.com.kotlininterstitialads

import com.google.android.gms.ads.AdListener
import com.google.android.gms.ads.AdRequest
import com.google.android.gms.ads.InterstitialAd
import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.widget.Button
import android.widget.Toast

class MainActivity : AppCompatActivity() {
    private var mLoadAdButton: Button? = null
    private var mInterstitialAd: InterstitialAd? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Create the InterstitialAd and set the adUnitId (defined in values/strings.xml).
        mInterstitialAd = newInterstitialAd()
        loadInterstitial()

        // Create the load ad button, tries to show an interstitial when clicked.
        mLoadAdButton = findViewById(R.id.load_ad_button) as Button
        mLoadAdButton!!.isEnabled = false
        mLoadAdButton!!.setOnClickListener {
            showInterstitial()
        }
    }

    private fun newInterstitialAd(): InterstitialAd {
        val interstitialAd = InterstitialAd(this)
        interstitialAd.adUnitId = getString(R.string.interstitial_ad_unit_id)
        interstitialAd.adListener = object : AdListener() {
            override fun onAdLoaded() {
                mLoadAdButton!!.isEnabled = true
                Toast.makeText(applicationContext, "Ad Loaded", Toast.LENGTH_SHORT).show()
            }

            override fun onAdFailedToLoad(errorCode: Int) {
                mLoadAdButton!!.isEnabled = true
                Toast.makeText(applicationContext, "Ad Failed To Load", Toast.LENGTH_SHORT).show()
            }

            override fun onAdClosed() {
                // Proceed to the next level.
               // goToNextLevel()
                Toast.makeText(applicationContext, "Ad Closed", Toast.LENGTH_SHORT).show()
                tryToLoadAdOnceAgain()
            }
        }
        return interstitialAd
    }

    private fun loadInterstitial() {
        // Disable the load ad button and load the ad.
        mLoadAdButton!!.isEnabled = false
        val adRequest = AdRequest.Builder().build()
        mInterstitialAd!!.loadAd(adRequest)
    }

    private fun showInterstitial() {
        // Show the ad if it is ready. Otherwise toast and reload the ad.
        if (mInterstitialAd != null && mInterstitialAd!!.isLoaded) {
            mInterstitialAd!!.show()
        } else {
            Toast.makeText(this, "Ad did not load", Toast.LENGTH_SHORT).show()
            tryToLoadAdOnceAgain()
        }
    }

    private fun tryToLoadAdOnceAgain() {
        mInterstitialAd = newInterstitialAd()
        loadInterstitial()
    }
}

AndroidManifest.xml

Add the following code in AndroidManifest.xml file:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="example.javatpoint.com.kotlininterstitialads">
    <!-- Include required permissions for Google Mobile Ads to run. -->
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"> <!-- This meta-data tag is required to use Google Play Services. -->
        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />

        <activity
            android:name=".MainActivity"
            android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity> <!-- Include the AdActivity configChanges and theme. -->
        <activity
            android:name="com.google.android.gms.ads.AdActivity"
            android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"
            android:theme="@android:style/Theme.Translucent" />
        <meta-data
            android:name="com.google.android.gms.ads.AD_MANAGER_APP"
            android:value="true"/>
    </application>

</manifest>

Output: