public class MainActivity extends Activity {  public RadioGroup mRadioGroup1;  public RadioButton mRadio1, mRadio2;  @Override  protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.activity_main);   mRadioGroup1 = (RadioGroup) findViewById(R.id.gendergroup);   mRadio1 = (RadioButton) findViewById(R.id.girl);   mRadio2 = (RadioButton) findViewById(R.id.boy);   mRadioGroup1.[b]setOnCheckedChangeListener[/b](radiogpchange);  }  private RadioGroup.[b]OnCheckedChangeListener[/b] radiogpchange = new RadioGroup.OnCheckedChangeListener() {   @Override   public void onCheckedChanged(RadioGroup group, int checkedId) {    if (checkedId == mRadio1.getId()) {     Toast.makeText(getApplicationContext(), "女孩", 1).show();    } else if (checkedId == mRadio2.getId()) {     Toast.makeText(getApplicationContext(), "男孩", 1).show();    }   }  }; }

    <RadioGroup         android:id="@+id/gendergroup"         android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:orientation="vertical" >         <RadioButton             android:id="@+id/girl"             android:layout_width="fill_parent"             android:layout_height="wrap_content"             android:text="@string/girl" />         <RadioButton             android:id="@+id/boy"             android:layout_width="fill_parent"             android:layout_height="wrap_content"             android:text="@string/boy" />     </RadioGroup>