How to programmatically add buttons into a layout one by one in several lines in Android

This example demonstrates how do I programmatically add buttons into a layout one by one several lines in android.

Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.

Step 2 − Add the following code to res/layout/activity_main.xml.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   tools:context=".MainActivity"
   android:orientation="vertical">
</LinearLayout>

Step 3 − Add the following code to src/MainActivity.java

package app.com.sample;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.LinearLayout;
public class MainActivity extends AppCompatActivity {
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      LinearLayout layout = new LinearLayout(this);
      layout.setOrientation(LinearLayout.VERTICAL);
      for (int i = 0; i < 3; i++) {
         LinearLayout row = new LinearLayout(this);
         row.setLayoutParams(new LinearLayout.LayoutParams
            (LinearLayout.LayoutParams.WRAP_CONTENT,
               LinearLayout.LayoutParams.WRAP_CONTENT));
         for (int j = 0; j < 4; j++) {
            Button btnTag = new Button(this);
            btnTag.setLayoutParams(new LinearLayout.LayoutParams
            (LinearLayout.LayoutParams.WRAP_CONTENT,
               LinearLayout.LayoutParams.MATCH_PARENT));
            btnTag.setText("Button " + (j + 1 + (i * 4 )));
            btnTag.setId(j + 1 + (i * 4));
            row.addView(btnTag);
         }
         layout.addView(row);
      }
      setContentView(layout);
   }
}

Step 4 - Add the following code to androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="app.com.sample">
   <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">
      <activity android:name=".MainActivity">
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click Run  icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen –

Click here to download the project code.