RadioGroup单选按钮用法

<RadioGroup
android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:checkedButton="@+id/b1"
    android:id="@+id/RG">
<!--默认选中b1-->
<RadioButton 
android:text="1"
        android:id="@+id/b1"
/>
<RadioButton 
android:text="2"
        android:id="@+id/b2"
/>
<RadioButton 
android:text="3"
        android:id="@+id/b3"
/>
</RadioGroup>
<Button 
android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:id="@+id/show"
    android:text="RadioGroup测试"
/>
<Button 
android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:id="@+id/clear"
    android:text="清除"
/>

package com.pocketdigi;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.RadioButton;
import android.widget.RadioGroup;

public class main extends Activity {
/** Called when the activity is first created. */
    @Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
        setTitle("RadioGroup测试");
        setContentView(R.layout.main);
        RGDemo();
    }
    RadioGroup rg;
    RadioButton b1;
    RadioButton b2;
    RadioButton b3;
public void RGDemo(){
        rg=(RadioGroup)findViewById(R.id.RG);
        b1=(RadioButton)findViewById(R.id.b1);
        b2=(RadioButton)findViewById(R.id.b2);
        b3=(RadioButton)findViewById(R.id.b3);
        Button clr=(Button)findViewById(R.id.clear);
        clr.setOnClickListener(clear);
        Button echo=(Button)findViewById(R.id.show);
        echo.setOnClickListener(show);
    }
private Button.OnClickListener clear=new OnClickListener(){

        @Override
public void onClick(View v) {
// TODO Auto-generated method stub
            rg.clearCheck();
            setTitle("RadioGroup测试");
        }

    };
private OnClickListener show=new OnClickListener(){

        @Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(b1.isChecked()){
                setTitle("1");
            }
if(b2.isChecked()){
                setTitle("2");
            }
if(b3.isChecked()){
                setTitle("3");
            }
        }

    };
}

 rg.setOnCheckedChangeListener(new OnCheckedChangeListener(){

            @Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
// TODO Auto-generated method stub
if(checkedId==b1.getId()){
                    Toast.makeText(main.this,"b1选中", Toast.LENGTH_LONG).show();
                }
if(checkedId==b2.getId()){
                    Toast.makeText(main.this,"b2选中", Toast.LENGTH_LONG).show();
                }
if(checkedId==b3.getId()){
                    Toast.makeText(main.this,"b3选中", Toast.LENGTH_LONG).show();
                }


            }

        });