PreferenceActivity: save value as integer

Question

Using a simple EditTextPreference in my preferences activity:

<EditTextPreference     android:key="SomeKey"     android:title="@string/some_title"     android:summary="..."     android:numeric="integer"     android:maxLength="2" /> 

Is there a way that this configuration value would be saved as integer? Seems now it just allows to enter numbers, but the value is still saved as string:

Calling:

SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this); int value = preferences.getInt("SomeKey", -1); 

throws me java.lang.ClassCastException: java.lang.String, and:

SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this); String value = preferences.getString("SomeKey", "-1"); 

retrieves the value successfully.

How to make PreferenceActivity to save value as integer by default?

Answer 1

You could extend EditTextPreference:

public class IntEditTextPreference extends EditTextPreference {      public IntEditTextPreference(Context context) {         super(context);     }      public IntEditTextPreference(Context context, AttributeSet attrs) {         super(context, attrs);     }      public IntEditTextPreference(Context context, AttributeSet attrs, int defStyle) {         super(context, attrs, defStyle);     }      @Override     protected String getPersistedString(String defaultReturnValue) {         return String.valueOf(getPersistedInt(-1));     }      @Override     protected boolean persistString(String value) {         return persistInt(Integer.valueOf(value));     } } 

It would be better to overwrite onSetInitialValue() and setText() methods, but then you would have to copy some code from a base class. Above solution is simplier, but it's quite tricky - "string" methods do something with ints. Try to not extend this class further ;-)

You could use it from XML by:

<package.name.IntEditTextPreference     android:key="SomeKey"     android:title="@string/some_title"     android:summary="..."     android:numeric="integer"     android:maxLength="2" />