<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="horizontal" >  <RadioGroup    android:id="@+id/radioGroup1"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:orientation="horizontal" >    <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></LinearLayout>

package com.example.hello;import android.support.v7.app.ActionBarActivity;import android.widget.RadioGroup;import android.widget.Toast;import android.widget.RadioGroup.OnCheckedChangeListener;import android.os.Bundle;public class MainActivity extends ActionBarActivity 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 void onCheckedChanged(RadioGroup group, int checkedId) {    switch(checkedId){      case R.id.radio0:        Toast.makeText(MainActivity.this, "男", 1).show();        break;      case R.id.radio1:        Toast.makeText(MainActivity.this, "女", 1).show();        break;    }  }}