【RadioGroup】实现单选并获得所选项值

Android RadioGroup有时候很有用，给用户提供多选一机制，现在要绘制一个画面，事例如下：

上面是一个TextView，下面有个RadioGroup，布局如下：

mian.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent">    <!--第一个TextView -->    <TextView        android:id="@+id/myTextView"        android:layout_width="228px"        android:layout_height="49px"        android:text="@string/str_radio_question1"        android:textSize="30sp"        />    <!--建立一个RadioGroup -->    <RadioGroup        android:id="@+id/myRadioGroup"        android:layout_width="137px"        android:layout_height="216px"        android:orientation="vertical">        <!--第一个RadioButton -->        <RadioButton            android:id="@+id/myRadioButton1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@string/tr_radio_op1"            />        <!--第二个RadioButton -->        <RadioButton            android:id="@+id/myRadioButton2"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@string/tr_radio_op2"            />    </RadioGroup></LinearLayout>

主控制程序 RadioGroupDemo.java：

?

package com.android.test; import android.app.Activity;import android.os.Bundle;import android.widget.RadioButton;import android.widget.RadioGroup;import android.widget.TextView; public class RadioGroupDemo extends Activity {    public TextView mTextView1;    public RadioGroup mRadioGroup1;    public RadioButton mRadio1, mRadio2;     public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);         // 取得 TextView、RadioGroup、RadioButton对象        mTextView1 = (TextView) findViewById(R.id.myTextView);        mRadioGroup1 = (RadioGroup) findViewById(R.id.myRadioGroup);        mRadio1 = (RadioButton) findViewById(R.id.myRadioButton1);        mRadio2 = (RadioButton) findViewById(R.id.myRadioButton2);         // RadioGroup用OnCheckedChangeListener来运行        mRadioGroup1.setOnCheckedChangeListener(mChangeRadio);    }     private RadioGroup.OnCheckedChangeListener mChangeRadio = new RadioGroup.OnCheckedChangeListener() {        @Override        public void onCheckedChanged(RadioGroup group, int checkedId) {            // TODO Auto-generated method stub            if (checkedId == mRadio1.getId()) {                // 把mRadio1的内容传到mTextView1                mTextView1.setText(mRadio1.getText());            } else if (checkedId == mRadio2.getId()) {                // 把mRadio2的内容传到mTextView1                mTextView1.setText(mRadio2.getText());            }        }    };}

需要注意的就是RadioGroup的消息处理。
mRadioGroup1.setOnCheckedChangeListener(mChangeRadio);