Android getting value from selected radiobutton

Question

I have a piece of code with three RadioButtons within a RadioGroup. I want to set an onCheckedListener that will show the value of the RadioButton in a Toast. However what I have gotten so far is not working. How do I get the value of the RadioButton and display it in a Toast? This is my code:

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;
import android.widget.Toast;

public class MainActivity extends Activity {

    RadioGroup rg;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        RadioGroup rg = (RadioGroup) findViewById(R.id.radioGroup1);
        final String value =
            ((RadioButton)findViewById(rg.getCheckedRadioButtonId()))
            .getText().toString();

        rg.setOnCheckedChangeListener(new OnCheckedChangeListener() {
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                Toast.makeText(getBaseContext(), value, Toast.LENGTH_SHORT).show();
            }
        });
    }
}

XML file:

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <RadioGroup
        android:id="@+id/radioGroup1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="152dp" >

        <RadioButton
            android:id="@+id/radio0"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Choose 1" />

         <RadioButton
            android:id="@+id/radio1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Choose 2" />

         <RadioButton
            android:id="@+id/radio2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Choose 3" />
     </RadioGroup>
 </RelativeLayout>

Autotruck

Answer 1

Tested and working. Check this

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 radioGroup;
  private RadioButton radioButton;
  private Button btnDisplay;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    addListenerOnButton();

  }

  public void addListenerOnButton() {

    radioGroup = (RadioGroup) findViewById(R.id.radio);
    btnDisplay = (Button) findViewById(R.id.btnDisplay);

    btnDisplay.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

                // get selected radio button from radioGroup
            int selectedId = radioGroup.getCheckedRadioButtonId();

            // find the radiobutton by returned id
            radioButton = (RadioButton) findViewById(selectedId);

            Toast.makeText(MyAndroidAppActivity.this,
                radioButton.getText(), Toast.LENGTH_SHORT).show();

        }

    });

  }
}

xml

<RadioGroup
        android:id="@+id/radio"
        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>

Unable

This is the thing u have seen from mykong link...instead of using button how can we get the selected id..for multiple radio group. – Praline

Perfect!!! answer... easy to get radio button view, when user will click !! – Wellman

Element with ID btnDisplay does not appear in your XML. – Gave

Answer 2

In case, if you want to do some job on the selection of one of the radio buttons (without having any additional OK button or something), your code is fine, updated little.

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        RadioGroup rg = (RadioGroup) findViewById(R.id.radioGroup1);

        rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() 
        {
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                switch(checkedId){
                    case R.id.radio0:
                        // do operations specific to this selection
                        break;
                    case R.id.radio1:
                        // do operations specific to this selection
                        break;
                    case R.id.radio2:
                        // do operations specific to this selection
                        break;
                }   
            }
        });
    }
}

Amphibology

Just a small correction, a very small one rather, you have declared 'rg' twice. It wont make a difference at all, just makes the code more readable. – Cota

@kaps faced this issue in api_31: #9093212 – Pippy

Answer 3

radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
       @Override
       public void onCheckedChanged(RadioGroup group, int checkedId)
       {
           radioButton = (RadioButton) findViewById(checkedId);
           Toast.makeText(getBaseContext(), radioButton.getText(), Toast.LENGTH_SHORT).show();
       }
   }
   );

Demonstration

Better answer than the accepted one, IMHO – Gave

That would be like this in kotlin and using binding. But it doesn't change anything if done with findViewById, it would just be findViewById<RadioGroup>. And the same for MaterialRadioButton, I use that one because I'm using material components, but it can be changed by RadioButton radioGroup.setOnCheckedChangeListener { group, checkedId -> val radioButton = findViewById<RadioButton>(checkedId) Toast.makeText(this, radioButton.text, Toast.LENGTH_SHORT).show() } – Halliehallman

Answer 4

int genid=gender.getCheckedRadioButtonId();
RadioButton radioButton = (RadioButton) findViewById(genid);
String gender=radioButton.getText().toString();

Hope this works. You can convert your output to string in the above manner. gender.getCheckedRadioButtonId(); - gender is the id of RadioGroup.

Debarath

works fine! but when I save the data into firebase and if I miss any Radio btn to check app crashed with "Attempt to invoke virtual method 'java.lang.CharSequence android.widget.RadioButton.getText()' on a null object reference" any solution – Nahama

maybe no radion button is selected, check radioButton != null before calling getText() – Incalescent

Answer 5

mRadioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(RadioGroup group, @IdRes int checkedId) {
        RadioButton radioButton = (RadioButton)group.findViewById(checkedId);
    }
});

Vanmeter

Answer 6

For anyone who is populating programmatically and looking to get an index, you might notice that the checkedId changes as you return to the activity/fragment and you re-add those radio buttons. One way to get around that is to set a tag with the index:

    for(int i = 0; i < myNames.length; i++) {
        rB = new RadioButton(getContext());
        rB.setText(myNames[i]);
        rB.setTag(i);
        myRadioGroup.addView(rB,i);
    }

Then in your listener:

    myRadioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(RadioGroup group, int checkedId) {
            RadioButton radioButton = (RadioButton) group.findViewById(checkedId);
            int mySelectedIndex = (int) radioButton.getTag();
        }
    });

Incoordinate

Answer 7

just use getCheckedRadioButtonId() function to determine wether if anything is checked, if -1 is the return value, you can avoid showing toast

Displume

Answer 8

Radiogroup rgteam;
String team;
rgteam.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(RadioGroup group, @IdRes int checkedId) {
            RadioButton rb= (RadioButton) findViewById(checkedId);
            team = rb.getText().toString();
        }
    });

Hispid

Answer 9

RadioGroup in XML

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">
<RadioGroup
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <RadioButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Java"/>

    </RadioGroup>
</RelativeLayout>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="150dp"
        android:layout_marginLeft="100dp"
        android:textSize="18dp"
        android:text="Select Your Course"
        android:textStyle="bold"
        android:id="@+id/txtView"/>
<RadioGroup
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:id="@+id/rdGroup"
    android:layout_below="@+id/txtView">
    <RadioButton
        android:id="@+id/rdbJava"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="10dp"
        android:layout_marginLeft="100dp"
        android:text="Java"
        android:onClick="onRadioButtonClicked"/>
    <RadioButton
        android:id="@+id/rdbPython"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="10dp"
        android:layout_marginLeft="100dp"
        android:text="Python"
        android:onClick="onRadioButtonClicked"/>
    <RadioButton
        android:id="@+id/rdbAndroid"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="10dp"
        android:layout_marginLeft="100dp"
        android:text="Android"
        android:onClick="onRadioButtonClicked"/>
    <RadioButton
        android:id="@+id/rdbAngular"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="10dp"
        android:layout_marginLeft="100dp"
        android:text="AngularJS"
        android:onClick="onRadioButtonClicked"/>
</RadioGroup>
    <Button
        android:id="@+id/getBtn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="100dp"
        android:layout_below="@+id/rdGroup"
        android:text="Get Course" />
</RelativeLayout>

MainActivity.java

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.RadioButton;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    RadioButton android, java, angular, python;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        android = (RadioButton)findViewById(R.id.rdbAndroid);
        angular = (RadioButton)findViewById(R.id.rdbAngular);
        java = (RadioButton)findViewById(R.id.rdbJava);
        python = (RadioButton)findViewById(R.id.rdbPython);
        Button btn = (Button)findViewById(R.id.getBtn);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String result = "Selected Course: ";
                result+= (android.isChecked())?"Android":(angular.isChecked())?"AngularJS":(java.isChecked())?"Java":(python.isChecked())?"Python":"";
                Toast.makeText(getApplicationContext(), result, Toast.LENGTH_SHORT).show();
            }
        });
    }
    public void onRadioButtonClicked(View view) {
        boolean checked = ((RadioButton) view).isChecked();
        String str="";
        // Check which radio button was clicked
        switch(view.getId()) {
            case R.id.rdbAndroid:
                if(checked)
                str = "Android Selected";
                break;
            case R.id.rdbAngular:
                if(checked)
                str = "AngularJS Selected";
                break;
            case R.id.rdbJava:
                if(checked)
                str = "Java Selected";
                break;
            case R.id.rdbPython:
                if(checked)
                str = "Python Selected";
                break;
        }
        Toast.makeText(getApplicationContext(), str, Toast.LENGTH_SHORT).show();
    }
}

Appalling

Answer 10

Thanks a lot to Chris.

This is my solution:

RadioGroup radgroup_opcionesEventos = null;


 private static String[] arrayEventos = {
            "Congestión", "Derrumbe", "Accidente"
    };
@Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        radgroup_opcionesEventos = (RadioGroup)findViewById(R.id.rg_opciones_evento);
        int i=0;//a.new.ln
        for(String evento : arrayEventos) {
            //RadioButton nuevoRadio = crearRadioButton(evento);//a.old.ln
            RadioButton nuevoRadio = crearRadioButton(evento,i);//a.new.ln
            radgroup_opcionesEventos.addView(nuevoRadio,i);
        }

        RadioButton primerRadio = (RadioButton) radgroup_opcionesEventos.getChildAt(0);
        primerRadio.setChecked(true);
}

private RadioButton crearRadioButton(String evento, int n)
    {
        //RadioButton nuevoRadio = new RadioButton(this);//a.old.ln
        RadioButton nuevoRadio = new RadioButton(getApplicationContext());//a.new.ln

        LinearLayout.LayoutParams params = new RadioGroup.LayoutParams(
                RadioGroup.LayoutParams.WRAP_CONTENT,
                RadioGroup.LayoutParams.WRAP_CONTENT);
        nuevoRadio.setLayoutParams(params);
        nuevoRadio.setText(evento);
        nuevoRadio.setTag(evento);
        return nuevoRadio;
    }


@Override
    protected void onResume()
    {
        radgroup_opcionesEventos.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                RadioButton radioButton = (RadioButton) group.findViewById(checkedId);
                //int mySelectedIndex = (int) radioButton.getTag();
                String mySelectedIndex = radioButton.getTag().toString();
            }
        });
        super.onResume();
    }

Shingles

Answer 11

I have had problems getting radio buttons id's as well when the RadioButtons are dynamically generated. It does not seem to work if you try to manually set the ID's using RadioButton.setId(). What worked for me was to use View.getChildAt() and View.getParent() in order to iterate through the radio buttons and determine which one was checked. All you need is to first get the RadioGroup via findViewById(R.id.myRadioGroup) and then iterate through it's children. You'll know as you iterate through which button you are on, and you can simply use RadioButton.isChecked() to determine if that is the button that was checked.

Marylynnmarylynne

If you check chinna's answer, that page is linked – Lovable

@AbrahamUribe can you review my edited answer and see if it's better than the previous one that was flagged? – Marylynnmarylynne

@mikeTheLiar you are correct, I did not notice the link in the original answer, that is my mistake. – Marylynnmarylynne

For this case, I believe the better solution is to use setTag(i), where i is the index of the array you're using to populate the radio group. I added an answer to show that way of doing it. – Incoordinate