How to save (switch) button state in android?
Use shared preferences or a database to store the state of your switch. It is essential that you depend on the lifecycle methods of Activity/fragment.
The following might help you:
@Override
public void onClick(View v)
{
if (toggle.isChecked())
{
SharedPreferences.Editor editor = getSharedPreferences("com.example.xyz", MODE_PRIVATE).edit();
editor.putBoolean("NameOfThingToSave", true);
editor.commit();
}
else
{
SharedPreferences.Editor editor = getSharedPreferences("com.example.xyz", MODE_PRIVATE).edit();
editor.putBoolean("NameOfThingToSave", false);
editor.commit();
}
}
The final nail:
@Override
protected void onCreate(Bundle savedInstanceState)
{
SharedPreferences sharedPrefs = getSharedPreferences("com.example.xyle", MODE_PRIVATE);
toggle.setChecked(sharedPrefs.getBoolean("NameOfThingToSave", true));
}
Edit:
The above code is working, however I feel it is a bad practice to get the shared preference values in onCreate, its better to make a loader class which inits your app variables well beforehand in a separate thread.
Update: Wed 24 Jul; 2019:
Android has view model support now - this can be used to handle switch state and persist it across sessions or configuration changes.