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：
主布局 main.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);
