title: RadioGroup.setEnabled(false) doesn't work as expected
body: <p>I have used <code>setEnabled(false)</code> to set it unable, but it doesn't work and after this method, the value of <code>RadioGroup.isEnabled()</code> is false. The value was changed.</p>
  
  <p>The code is from Android Programming Guide.</p>
  
  <p>PS: The <code>Spinner</code> component use the <code>setEnabled(false)</code> as well.</p>
  
  <p>Code is as follows:</p>
  
  <pre><code>import android.app.Activity;
  import android.graphics.Color;
  import android.os.Bundle;
  import android.view.View;
  import android.view.View.OnClickListener;
  import android.widget.Button;
  import android.widget.RadioGroup;
  
  public class TestRadioGroup extends Activity {
  
  
  @Override
  public void onCreate(Bundle savedInstanceState) {
      // TODO Auto-generated method stub
      super.onCreate(savedInstanceState);
      setContentView(R.layout.radiogroup);
  
      final RadioGroup testRadioGroup = (RadioGroup) findViewById(R.id.testRadioGroup);
  
      final Button changeEnabledButton = (Button) findViewById(R.id.changeEnabledButton);
      changeEnabledButton.setOnClickListener(new OnClickListener() {
  
          public void onClick(View v) {
              // TODO Auto-generated method stub
              changeEnabled(testRadioGroup);
          }
      });
  
      final Button changeBgColorButton = (Button) findViewById(R.id.changeBackgroundColorButton);
      changeBgColorButton.setOnClickListener(new OnClickListener() {
  
          public void onClick(View v) {
              // TODO Auto-generated method stub
              changeBgColor(testRadioGroup);
          }
      });
  
  }
  
  protected void changeBgColor(RadioGroup testRadioGroup) {
      // TODO Auto-generated method stub
      testRadioGroup.setBackgroundColor(Color.BLUE);
  }
  
  protected void changeEnabled(RadioGroup testRadioGroup) {
      // TODO Auto-generated method stub
      if (testRadioGroup.isEnabled()) {
          testRadioGroup.setEnabled(false);
      } else {
          testRadioGroup.setEnabled(true);
      }
  }
  </code></pre>
  
  <p>}</p>