<?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="vertical">
  <!--
   RadioButton 要想實現(xiàn)多選一的效果必須放到RadioGroup 中,否則無法實現(xiàn)多選一的效果.
   技巧:要面向RadioGroup 編程,不要面向RaidoButton 編程,否則將增加很大代碼量
   android:orientation="vertical":執(zhí)行按鈕組的方向,默認值是vertical.
   RadioGroup的父類時LinearLayout,但方向的默認值不再是線性布局的水平方向了,而是改成了垂直方向.
   -->
  <RadioGroup
    android:id="@+id/radioGroup_gender"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:orientation="vertical"
    >
    <RadioButton
      android:id="@+id/radioButton_male"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_gravity="center_horizontal"
      android:checked="true"
      android:text="男" />
    <RadioButton
      android:id="@+id/radioButton_female"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_gravity="center_horizontal"
      android:checked="false"
      android:text="女" />
  </RadioGroup>
</LinearLayout>

package com.hsj.example.commoncontroldemo02;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;

public class MainActivity_bak06 extends AppCompatActivity implements RadioGroup.OnCheckedChangeListener {

  private RadioGroup radioGroup_gender;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_radio);
    this.radioGroup_gender= (RadioGroup) this.findViewById(R.id.radioGroup_gender);
    this.radioGroup_gender.setOnCheckedChangeListener(this);

  }

  /**
   * 當單選按鈕的狀態(tài)發(fā)生變化時自動調用的方法
   * @param group 單選按鈕所在的按鈕組的對象
   * @param checkedId 用戶選中的單選按鈕的id值
   */
  @Override
  public void onCheckedChanged(RadioGroup group, int checkedId) {
    //得到用戶選中的 RadioButton 對象
    RadioButton radioButton_checked= (RadioButton) group.findViewById(checkedId);
    String gender=radioButton_checked.getText().toString();
    Toast.makeText(this,gender,Toast.LENGTH_LONG).show();
    switch (checkedId){
      case R.id.radioButton_male:
        //當用戶點擊男性按鈕時執(zhí)行的代碼
        System.out.println("===男性===");
        break;
      case R.id.radioButton_female:
        //當用戶點擊女性按鈕時執(zhí)行的代碼
        System.out.println("===女性===");
        break;
    }
    System.out.println("===onCheckedChanged(RadioGroup group="+group+", int checkedId="+checkedId+")==");
  }
}