无法在Android中保存CheckBox的状态

Question

I am developing an application. There are many checkbox in one page. I want to save the state of CheckBox when I exit page. I use SharedPreferrences to save. The code is like this:

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();
    }

});

When I leave this page, and back again. All the checkbox state becomes not selected as default. why?

Answer 1

You are saving vallues but you have to restore them you your activity is started like this :

SharedPreferences prefs = getSharedPreferences("syllabus", 0);
checkbox1.setChecked(prefs.getBoolean("cbx1_ischecked" ,false));
checkbox2.setChecked(prefs.getBoolean("cbx2_ischecked" ,false));

Answer 2

try this

 boolean check1,check2;
 checkbox1.setOnCheckedChangeListener(new OnCheckedChangeListener(){
 public void onCheckedChanged(CompoundButton arg0, boolean isChecked) {
 // TODO Auto-generated method stub
  check1=isChecked;

 }
});

checkbox2.setOnCheckedChangeListener(new OnCheckedChangeListener(){
public void onCheckedChanged(CompoundButton arg0, boolean isChecked) {
// TODO Auto-generated method stub
 check2=isChecked;

}

}); 

//store boolean only once when you leave the activity
 Editor editor = getSharedPreferences("syllabus", 0).edit();
 editor.putBoolean("cbx1_ischecked", check1);
 editor.putBoolean("cbx2_ischecked", check2);
 editor.commit();


 In onCreate()

  SharedPreferences prefs = getSharedPreferences("syllabus", 0);
  checkbox1.setChecked(prefs.getBoolean("cbx1_ischecked" ,false));
  checkbox2.setChecked(prefs.getBoolean("cbx2_ischecked" ,false));