RadioGroup和RadioButton的使用

RadioGroup和RadioButton代表的是Android中单选按钮的一种控件，写个简单的代码熟悉一下：

import android.app.Activity;
import android.os.Bundle;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;
import android.widget.TextView;

public class Radio extends Activity {
    private TextView myTextView;
    private RadioButton chinaBtn;
    private RadioButton ukBtn;
    private RadioButton usaBtn;
    private RadioGroup rg;
    
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //通过ID找到TextView
        myTextView = (TextView) findViewById(R.id.myTextView);
        //通过ID找到RadioButton
        chinaBtn = (RadioButton) findViewById(R.id.china_Button);
        ukBtn = (RadioButton) findViewById(R.id.uk_Button);
        usaBtn = (RadioButton) findViewById(R.id.usa_Button);
        //通过ID找到RadioGroup
        rg = (RadioGroup) findViewById(R.id.rBtnGroup);
        
        //只要对RadioGroup进行监听
        rg.setOnCheckedChangeListener(new OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                // TODO Auto-generated method stub
                if(R.id.china_Button == checkedId){
                    myTextView.setText("您选择的国家是：" + chinaBtn.getText().toString());
                }
                else if(R.id.uk_Button == checkedId){
                    myTextView.setText("您选择的国家是：" + ukBtn.getText().toString());
                }
                else if(R.id.usa_Button == checkedId){
                    myTextView.setText("您选择的国家是：" + usaBtn.getText().toString());
                }
            }
        });
    }
}

main.xml文件如下：

<?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"
    >
    <TextView  
        android:id="@+id/myTextView"
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:text="@string/hello"
    />
    <RadioGroup android:id="@+id/rBtnGroup"
                android:layout_width="wrap_content" 
                android:layout_height="wrap_content" 
                >
        <RadioButton
            android:id="@+id/china_Button"
            android:layout_width="wrap_content" 
            android:layout_height="wrap_content" 
            android:text="中国"
        />
        <RadioButton
            android:id="@+id/uk_Button"
            android:layout_width="wrap_content" 
            android:layout_height="wrap_content" 
            android:text="英国"
        />
        <RadioButton
            android:id="@+id/usa_Button"
            android:layout_width="wrap_content" 
            android:layout_height="wrap_content" 
            android:text="美国"
        />
    </RadioGroup>
</LinearLayout>

效果如下：