How to set the value for the attribute layout_weight for button in Android dynamically from java code?

This example demonstrates how do I set the value for the attribute layout_weight for button in android dynamically from java code.

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="match_parent"
   android:layout_height="match_parent"
   android:orientation="horizontal"
   android:gravity="center"
   android:id="@+id/linearLayout"
   android:padding="4dp"
   tools:context=".MainActivity">
</LinearLayout>

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

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.LinearLayout;
public class MainActivity extends AppCompatActivity {
   LinearLayout linearLayout;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      linearLayout = findViewById(R.id.linearLayout);
      LinearLayout.LayoutParams params1 = new LinearLayout.LayoutParams(
      LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
      params1.weight = 0.3f;
      Button button1 = new Button(this);
      button1.setText("Button 1");
      button1.setLayoutParams(params1);
      linearLayout.addView(button1);
      LinearLayout.LayoutParams params2 = new LinearLayout.LayoutParams(
      LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
      params2.weight = 0.7f;
      Button button2 = new Button(this);
      button2.setText("Button 2");
      button2.setLayoutParams(params2);
      linearLayout.addView(button2);
   }
}

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 the android studio, open one of your project's activity files and click the Run   icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen −

Azhar

Published on 30-Oct-2019 11:55:18