Radio Button Demo

Radio Button Demo

1. Custom String

Open “res/values/strings.xml” file, add some custom string for radio button.

File : res/values/strings.xml

<?xml version="1.0" encoding="utf-8"?>

<resources>

    <string name="hello">Hello World, MyAndroidAppActivity!</string>

    <string name="app_name">MyAndroidApp</string>

    <string name="radio_male">Male</string>

    <string name="radio_female">Female</string>

    <string name="btn_display">Display</string>

</resources>

2. RadioButton

Open “res/layout/main.xml” file, add “RadioGroup“, “RadioButton” and a button, inside the LinearLayout.

File : res/layout/main.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:orientation="vertical" >

    <RadioGroup

        android:id="@+id/radioSex"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content" >

        <RadioButton

            android:id="@+id/radioMale"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="@string/radio_male"

            android:checked="true" />

        <RadioButton

            android:id="@+id/radioFemale"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="@string/radio_female" />

    </RadioGroup>

    <Button

        android:id="@+id/btnDisplay"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="@string/btn_display" />

</LinearLayout>

Radio button selected by default.
To make a radio button is selected by default, put android:checked="true" within the RadioButton element. In this case, radio option “Male” is selected by default.

3. Code Code

Inside activity “onCreate()” method, attach a click listener on button.

File : MyAndroidAppActivity.java

package com.mkyong.android;

import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.RadioButton;

import android.widget.RadioGroup;

import android.widget.Toast;

public class MyAndroidAppActivity extends Activity {

  private RadioGroup radioSexGroup;

  private RadioButton radioSexButton;

  private Button btnDisplay;

  @Override

  public void onCreate(Bundle savedInstanceState) {

         super.onCreate(savedInstanceState);

         setContentView(R.layout.main);

         addListenerOnButton();

  }

  public void addListenerOnButton() {

         radioSexGroup = (RadioGroup) findViewById(R.id.radioSex);

         btnDisplay = (Button) findViewById(R.id.btnDisplay);

         btnDisplay.setOnClickListener(new OnClickListener() {

                  @Override

                  public void onClick(View v) {

                         // get selected radio button from radioGroup

                          int selectedId = radioSexGroup.getCheckedRadioButtonId();

                          // find the radiobutton by returned id

                         radioSexButton = (RadioButton) findViewById(selectedId);

                          Toast.makeText(MyAndroidAppActivity.this,

                                   radioSexButton.getText(), Toast.LENGTH_SHORT).show();

                  }

         });

  }

}

4. Demo

Run the application.

1. Result, radio option “Male” is selected.

Download it – Android-RadioButton-Example.zip (15 KB)