radioGroup可以实现单选

注意 OnCheckedChangeListener() 为radioGroup的方法，需要import android.widget.RadioGroup.OnCheckedChangeListener;

而onCheckedChanged() 方法的checkedId参数为被选中radioButton的ID，可以在switch的case中用R.id.radio0的形式去匹配。

当然，也可以单个的RadioButton来实现监听，而不是用RadioGroup判断ID 的形式。

package com.example.test_radio_group;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;

public class MainActivity extends Activity implements OnCheckedChangeListener{
private RadioGroup rg;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    rg = (RadioGroup) findViewById(R.id.radioGroup1);
    rg.setOnCheckedChangeListener(this);

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
    RadioButton rb;
    String mtext;
    rb = (RadioButton) findViewById(checkedId);
    mtext = rb.getText().toString();
    switch(checkedId){
    case R.id.radio0:
        Log.i("log", mtext);
        break;
    case R.id.radio1:
        Log.i("log", mtext);
        break;
    default:
        break;

    }

}

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.test_radio_group.MainActivity" >

<RadioGroup
    android:id="@+id/radioGroup1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:orientation="horizontal"
    android:layout_alignParentTop="true" >

    <RadioButton
        android:id="@+id/radio0"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:checked="true"
        android:text="男" />

    <RadioButton
        android:id="@+id/radio1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="女" />

</RadioGroup>

</RelativeLayout>