How can I access the value of a radio button in Android?

In Android, you can retrieve the value of a radio button by using the following method:

1. Firstly, define a RadioGroup and several RadioButtons in the layout file, giving each RadioButton a unique id.
2. In the Activity, use the findViewById method to obtain a RadioGroup object and set an OnCheckedChangeListener listener to monitor changes in the radio buttons’ selection.
3. In the callback method of OnCheckedChangeListener, you can retrieve the id of the selected radio button using the getCheckedRadioButtonId method.
4. Finally, by using the findViewById method along with the id of the selected radio button, you can obtain the corresponding RadioButton object and retrieve its displayed text value using the getText method.

The sample code is as follows:

Define a radio button group and radio button in the layout file.

<RadioGroup
    android:id="@+id/radioGroup"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <RadioButton
        android:id="@+id/radioButton1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Option 1" />

    <RadioButton
        android:id="@+id/radioButton2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Option 2" />

    <RadioButton
        android:id="@+id/radioButton3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Option 3" />

</RadioGroup>

Retrieve the value of a radio button in an Activity:

RadioGroup radioGroup = findViewById(R.id.radioGroup);
radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(RadioGroup group, int checkedId) {
        RadioButton radioButton = findViewById(checkedId);
        String selectedValue = radioButton.getText().toString();
        // 处理选中的值
    }
});