How to get the selected index of a RadioGroup in Android

user_2847 0
Viewed 237529

Is there an easy way to get the selected index of a RadioGroup in Android or do I have to use OnCheckedChangeListener to listen for changes and have something that holds the last index selected?

example xml:

<RadioGroup android:id="@+id/group1" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="vertical">
    <RadioButton android:id="@+id/radio1" android:text="option 1" android:layout_width="wrap_content" android:layout_height="wrap_content" />
    <RadioButton android:id="@+id/radio2" android:text="option 2" android:layout_width="wrap_content" android:layout_height="wrap_content" />
    <RadioButton android:id="@+id/radio3" android:text="option 3" android:layout_width="wrap_content" android:layout_height="wrap_content" />
    <RadioButton android:id="@+id/radio4" android:text="option 4" android:layout_width="wrap_content" android:layout_height="wrap_content" />
    <RadioButton android:id="@+id/radio5" android:text="option 5" android:layout_width="wrap_content" android:layout_height="wrap_content" />
</RadioGroup>

if a user selects option 3 I want to get the index, 2.

radio-group android xml java
19 Answers

Kotlin:

val selectedIndex = radioButtonGroup?.indexOfChild(
  radioButtonGroup?.findViewById(
    radioButtonGroup.getCheckedRadioButtonId())
)
user_57666700

Late to the party, but here is a simplification of @Tarek360's Kotlin answer that caters for RadioGroups that might contain non-RadioButtons:

    val RadioGroup.checkedIndex: Int
        get() = children
            .filter { it is RadioButton }
            .indexOfFirst { it.id == checkedRadioButtonId }

If you're RadioFroup definitely only has RadioButtons then this can be a simple as:

    private val RadioGroup.checkedIndex = 
        children.indexOfFirst { it.id == checkedRadioButtonId }

Then you don't have the overhead of findViewById.

user_10896290

Here is a Kotlin extension to get the correct position even if your group contains a TextView or any non-RadioButton.

fun RadioGroup.getCheckedRadioButtonPosition(): Int {
    val radioButtonId = checkedRadioButtonId
    return children.filter { it is RadioButton }
        .mapIndexed { index: Int, view: View ->
            index to view
        }.firstOrNull {
            it.second.id == radioButtonId
        }?.first ?: -1
}
user_33112190

You can simply

-declare the radio group and a radio button out of onCreate method

private RadioGroup GrupName;
private RadioButton NameButton;

-set the view id in the onCreate method

GrupName = (RadioGroup) findViewById(R.id.radioGroupid);

-take the radiobutton id selected using

int id = GroupName.getCheckedRadioButtonId();

-use the id to match the buttonselected view

NameButton = (RadioButton) findViewById(id);

-finally get the value of the radio button

String valueExpected = NameButton.getText().toString();

--- PS: IF YOU WANT AN INT VALUE, THEN YOU CAN CAST IT

int valueExpectedIn = Integer.parseInt(valueExpected);
user_112616840 
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(MainActivity.this,radioSexButton.getText(),Toast.LENGTH_SHORT).show();
        }
    });
user_91505840

You have already assigned an id for each radio button. With a case block you can detect manually the selected radio button or with OnCheckedChangeListener you get it too.

xml:

    <RadioGroup
        android:id="@+id/rd_group_pick_reason"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@id/ti_titel"
        android:orientation="horizontal"
        android:paddingHorizontal="16dp"
        >
        <com.google.android.material.radiobutton.MaterialRadioButton
            android:id="@+id/rd_not_deliverable"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="0.5"
            android:text="@string/txt_not_deliverable"
            android:checked="true"
            />

        <com.google.android.material.radiobutton.MaterialRadioButton
            android:id="@+id/rd_after_pack"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="0.5"
            android:text="@string/txt_after_pack"
            />
    </RadioGroup>

java:

final RadioGroup radioGroup = dialogView.findViewById(R.id.rd_group_pick_reason);    
switch (radioGroup.getCheckedRadioButtonId()) {
    case R.id.rd_not_deliverable:
        // TODO
    break;
    case R.id.rd_after_pack:
        // TODO
    break;
}

or

radioGroup.setOnCheckedChangeListener((group, checkedId) -> {
    switch (group.getCheckedRadioButtonId()) {
        case R.id.rd_not_deliverable:
            System.out.println("not deliverable");
            break;
        case R.id.rd_after_pack:
            System.out.println("after pack");
            break;
    }
user_39640990
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