title: How to save state of CheckBox after exit?
body: <p>In my app ,one interface has some checkBoxes,I wish after I exit the interface, the CheckBoxes should maintain the state.So next time I enter it can show what I have done last time.I have used <code>SharedPreferrences</code> to achieve this. </p>
  
  <pre><code>checkbox1.setOnCheckedChangeListener(new OnCheckedChangeListener(){
      public void onCheckedChanged(CompoundButton arg0, boolean isChecked) {
  // TODO Auto-generated method stub
  Editor editor = getSharedPreferences("syllabus", 0).edit();
  editor.putBoolean("cbx1_ischecked", isChecked);
  editor.commit();
  }
      });
  checkbox2.setOnCheckedChangeListener(new OnCheckedChangeListener(){
      public void onCheckedChanged(CompoundButton arg0, boolean isChecked) {
      // TODO Auto-generated method stub
      Editor editor = getSharedPreferences("syllabus", 0).edit();
      editor.putBoolean("cbx2_ischecked", isChecked);
      editor.commit();
      }
  
  });
  </code></pre>
  
  <p>But it doesn't work. when I return to this page, All checkBox show state that "every item is unselected ".</p>
  
  <p>How can I realize the function I wish?</p>