How can write code to make sharedpreferences for array in android?
I am working in android. I want to make sharedpreference in my code, but i dont know the way by which i can make a sharedpreference for array and how can use the value of that sharedpreference in another class.
This is my array in one for loop :- urls[i]=sitesList.getWebsite().get(i);
i want to make share preference of this urls[] array. please sug开发者_C百科gest me how can i write code to declare sharedpreference and how can i retrieve value of that sharedpreference ?
Thank you in advance.
putStringSet
and getStringSet
are only available in API 11.
Alternatively you could serialize your arrays using JSON like so:
public static void setStringArrayPref(Context context, String key, ArrayList<String> values) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = prefs.edit();
JSONArray a = new JSONArray();
for (int i = 0; i < values.size(); i++) {
a.put(values.get(i));
}
if (!values.isEmpty()) {
editor.putString(key, a.toString());
} else {
editor.putString(key, null);
}
editor.commit();
}
public static ArrayList<String> getStringArrayPref(Context context, String key) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
String json = prefs.getString(key, null);
ArrayList<String> urls = new ArrayList<String>();
if (json != null) {
try {
JSONArray a = new JSONArray(json);
for (int i = 0; i < a.length(); i++) {
String url = a.optString(i);
urls.add(url);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
return urls;
}
Set and retreive your URLs like so:
// store preference
ArrayList<String> list = new ArrayList<String>(Arrays.asList(urls));
setStringArrayPref(this, "urls", list);
// retrieve preference
list = getStringArrayPref(this, "urls");
urls = (String[]) list.toArray();
精彩评论