Get the array of RadioButtons in a RadioGroup in Android

Is there any way of getting an array (or a collection) of the RadioButtons in an Android开发者_开发问答 RadioGroup? I would like to add individual listeners to radio buttons but I don't see any obvious way of iterating over them.

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this should do the trick:

        int count = radioGroup.getChildCount();
        ArrayList<RadioButton> listOfRadioButtons = new ArrayList<RadioButton>();
        for (int i=0;i<count;i++) {
            View o = radioGroup.getChildAt(i);
            if (o instanceof RadioButton) {
                listOfRadioButtons.add((RadioButton)o);
            }
        }
        Log.d(TAG,"you have "+listOfRadioButtons.size()+" radio buttons");

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Why do you need to query the radioGroup? Why cant you directly set your listeners on the RadioButton, you must be able to get a hold of the radioButtons since you are the one who is adding them to the RadioGroup.

Regardless, RadioGroup is simply a special type of LinearLayout, all its children are RadioButtons that you have added. You can loop through all the child views to access the RadioButtons.

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Working example for RadioGroup with five RadioButtons (Kotlin):

private fun initUIListeners() {    
    with(binding) {
        rb1.setOnClickListener(rbClick(radioGroup))
        rb2.setOnClickListener(rbClick(radioGroup))
        rb3.setOnClickListener(rbClick(radioGroup))
        rb4.setOnClickListener(rbClick(radioGroup))
        rb5.setOnClickListener(rbClick(radioGroup))
    }
}

private fun rbClick(radioGroup: RadioGroup): (View) -> Unit = {
    val radioButton = it as MaterialRadioButton
    when {
        !radioButton.isSelected -> {
            radioButton.isChecked = true
            radioButton.isSelected = true
            unselectExcept(radioButton, radioGroup)
        }
        else -> {
            radioButton.isChecked = false
            radioButton.isSelected = false
            radioGroup.clearCheck()
        }
    }
}

private fun unselectExcept(
    radioButton: MaterialRadioButton,
    radioGroup: RadioGroup,
) = (0 until radioGroup.childCount)
    .map { radioGroup.getChildAt(it) }
    .filterIsInstance<MaterialRadioButton>()
    .filter { it != radioButton }
    .forEach { it.isSelected = false }