如何以编程方式在屏幕底部显示 AdMob 横幅广告？（Kotlin）

Question

I'm new to Kotlin and Android. I want to display an AdMob banner ad at the bottom of the screen programmatically. But I can only display it at the top of the screen. Here is my code:

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/activityMain"
    tools:context=".MainActivity">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:adjustViewBounds="false"
        android:scaleType="centerCrop"
        android:id="@+id/rootImageView"
        />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:id="@+id/testTextView"
        />

</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.kt:

import android.app.Notification
import android.content.res.Configuration
import android.graphics.Color
import android.media.AudioManager
import android.media.MediaPlayer
import android.media.ToneGenerator
import android.os.Build
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.provider.MediaStore
import android.view.View
import android.view.WindowManager
import android.widget.Toast
import androidx.annotation.RequiresApi
import androidx.constraintlayout.widget.ConstraintLayout
import com.google.android.gms.ads.AdRequest
import com.google.android.gms.ads.AdSize
import com.google.android.gms.ads.AdView
import com.google.android.gms.ads.MobileAds
import kotlinx.android.synthetic.main.activity_main.*

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

        if(useAdMob){ initAdMob(); }
    }
    //---------------------------------------------
    fun initAdMob()
    {
        MobileAds.initialize(this);

        val adView = AdView(this);
        adView.adSize = AdSize.BANNER;
        adView.adUnitId = if(testAdMob) idAdMobBannerForTest else idAdMobBanner1;
        val adRequest = AdRequest.Builder().build();
        adView.loadAd(adRequest);

        activityMain.addView(adView);
        adView.setBackgroundColor(Color.RED);
        
        val lp = adView.layoutParams;
        lp.width = WindowManager.LayoutParams.MATCH_PARENT;
        lp.height = WindowManager.LayoutParams.WRAP_CONTENT;
        println(">>>> adView, width: ${lp.width}, height: ${lp.height}");
    }
}

I've searched a lot for the solution, for example, try to:

addRule(RelativeLayout.ALIGN_PARENT_BOTTOM)

or add in xml:

android:layout_alignParentBottom="true"

But these seems unavailable in the newest version of Android Studio. Please help me. Thanks in advance.

Answer 1

I would advise not doing this programatically, but you can use ConstraintSet to set Constraint layout rules programatically. Looks something like this:

adView.id = View.generateViewId() // Need to give view an id

ConstraintSet().apply {
    connect(adView.id, ConstraintSet.BOTTOM, ConstraintSet.PARENT_ID, ConstraintSet.BOTTOM)
    applyTo(constraintLayout) // Your constraint layout here
}

This is equivalent to in xml doing

app:layout_constraintBottom_toBottomOf="parent"

Answer 2

Since you use constraint layout try this below code...

<com.google.android.gms.ads.AdView
   xmlns:ads="http://schemas.android.com/apk/res-auto"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:id="@+id/bannerAd"
   ads:adUnitId="ca-app-pub-3940256099942544/6300978111"
   app:layout_constraintBottom_toBottomOf="parent"
   app:layout_constraintStart_toStartOf="parent"
   app:layout_constraintEnd_toEndOf="parent"/>

and in kotlin file

MobileAds.initialize(this) {}
    var mAdView = findViewById(R.id.bannerAd)
    val adRequest = AdRequest.Builder().build()
    mAdView.loadAd(adRequest)