RadioGroup radioGroup = findViewById(R.id.radioGroup);
RadioButton radioButton = findViewById(R.id.radioButton1);
radioButton.setChecked(true);

RadioGroup radioGroup = findViewById(R.id.radioGroup);
radioGroup.check(R.id.radioButton2); // 通过RadioButton的ID

RadioGroup radioGroup = findViewById(R.id.radioGroup);
RadioButton radioButton = (RadioButton) radioGroup.getChildAt(0); // 获取第一个RadioButton
radioButton.setChecked(true);

int selectedId = radioGroup.getCheckedRadioButtonId();
RadioButton selectedRadioButton = findViewById(selectedId);
String selectedText = selectedRadioButton.getText().toString();

radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(RadioGroup group, int checkedId) {
        // 处理选择变化
        RadioButton radioButton = findViewById(checkedId);
        Log.d("RadioGroup", "Selected: " + radioButton.getText());
    }
});

RadioButton newRadio = new RadioButton(this);
newRadio.setId(View.generateViewId()); // 生成唯一ID
radioGroup.addView(newRadio);
radioGroup.check(newRadio.getId());