package com.cloud.test;

import Android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.widget.RadioButton;

public class MyRadioButton extends RadioButton{

public MyRadioButton(Context context) {
  super(context);
}

public MyRadioButton(Context context,AttributeSet attrs) {
  super(context,attrs);
}

@Override
public boolean isChecked() {
  return super.isChecked();
}

@Override
public void setButtonDrawable(int resid) {
  super.setButtonDrawable(resid);
}

@Override
protected void onDraw(Canvas canvas) {
  if(isChecked()){
   super.setButtonDrawable(R.drawable.circle_green);    //為選中RadioButton的圖片
  }else{
super.setButtonDrawable(R.drawable.circle_grey); //未選中RadioButton的圖片
  }
  super.onDraw(canvas);
}

}

package com.cloud.test;

import android.app.Activity;
import android.os.Bundle;
import android.widget.LinearLayout;
import android.widget.RadioGroup;

public class RadioButtonTestActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        LinearLayout layout=(LinearLayout)findViewById(R.id.layout);
        RadioGroup rg=new RadioGroup(this);
        MyRadioButton mBtn=new MyRadioButton(getApplicationContext());
        mBtn.setWidth(100);
        mBtn.setText("RadioBtnOne");
        mBtn.setHeight(60);
        
        MyRadioButton mBtn2=new MyRadioButton(getApplicationContext());
        mBtn2.setWidth(100);
        mBtn2.setText("RadioBtnTwo");

       mBtn2.setHeight(60);

        rg.addView(mBtn);
        rg.addView(mBtn2);
        layout.addView(rg);
        
    }

}

轉載自:http://blog.csdn.net/zurich1979/article/details/7276420