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Radio Buttons

In this document

  1. Responding to Click Events

Key classes

  1. RadioButton
  2. RadioGroup

Radio buttons allow the user to select one option from a set. You should use radio buttons for optional sets that are mutually exclusive if you think that the user needs to see all available options side-by-side. If it's not necessary to show all options side-by-side, use a spinner instead.

To create each radio button option, create a RadioButton in your layout. However, because radio buttons are mutually exclusive, you must group them together inside a RadioGroup. By grouping them together, the system ensures that only one radio button can be selected at a time.

Responding to Click Events

When the user selects one of the radio buttons, the corresponding RadioButton object receives an on-click event.

To define the click event handler for a button, add the android:onClick attribute to the <RadioButton> element in your XML layout. The value for this attribute must be the name of the method you want to call in response to a click event. The Activity hosting the layout must then implement the corresponding method.

For example, here are a couple RadioButton objects:

<?xml version="1.0" encoding="utf-8"?>
<RadioGroup xmlns:android=""
    <RadioButton android:id="@+id/radio_pirates"
    <RadioButton android:id="@+id/radio_ninjas"

Note: The RadioGroup is a subclass of LinearLayout that has a vertical orientation by default.

Within the Activity that hosts this layout, the following method handles the click event for both radio buttons:

public void onRadioButtonClicked(View view) {
    // Is the button now checked?
    boolean checked = (RadioButton) view).isChecked();
    // Check which radio button was clicked
    switch(view.getId()) {
            if (checked)
                // Pirates are the best
            if (checked)
                // Ninjas rule

The method you declare in the android:onClick attribute must have a signature exactly as shown above. Specifically, the method must:

  • Be public
  • Return void
  • Define a View as its only parameter (this will be the View that was clicked)

Tip: If you need to change the radio button state yourself (such as when loading a saved CheckBoxPreference), use the setChecked(boolean) or toggle() method.