Dynamic ListPreference in android

Question

How to generate dynamic listPreference in android? I want to get all wifi access points and make a list using in preference Activity(i.e. make a list using listpreference). How to do this?

Solution 1

Every XML element in Android can be created programmatically as the element name is also a Java class. Hence you can create a ListPreference in code:

CharSequence[] entries = { "One", "Two", "Three" };
CharSequence[] entryValues = { "1", "2", "3" };
ListPreference lp = new ListPreference(this);
lp.setEntries(entries);
lp.setEntryValues(entryValues);

You could alternatively create it in XML then add the entries/entry values in code:

CharSequence[] entries = { "One", "Two", "Three" };
CharSequence[] entryValues = { "1", "2", "3" };
ListPreference lp = (ListPreference)findPreference("list_key_as_defined_in_xml");
lp.setEntries(entries);
lp.setEntryValues(entryValues);

Solution 2

For creating a dynamic list preference, u need to create a preference activity (ie to extend an activity as PreferenceActivity).

The following code can be used to create the list dynamically.

// Root
        PreferenceScreen root = getPreferenceManager().createPreferenceScreen(this);
        dialogBasedPrefCat.setTitle("Category Title");
        root.addPreference(dialogBasedPrefCat); //Adding a category

 // List preference under the category
        ListPreference listPref = new ListPreference(this);
        listPref.setKey("keyName"); //Refer to get the pref value
        listPref.setEntries("Array of values");
        listPref.setEntryValues("Array of item value");
        listPref.setDialogTitle("Dialog Title"); 
        listPref.setTitle("Title");
        listPref.setSummary("Summary");
        dialogBasedPrefCat.addPreference(listPref); Adding under the category

        return root;

Hope this helps to get an !dea...

EDIT:

Create and add values to CharSequence[] like this:

CharSequence[] cs = new String[]{"myValue"};

Comments

[ccpizza]

Considering that the items will be dynamic it is not enough to set the items in onCreate. You also need to update the values when the ListPreference is clicked: stackoverflow.com/questions/6474707/…

[Spacen Jasset]

findViewById works with views. ListPreference isn't a view, so the second example doesn't seem to work. Can't cast.

[Boris van Schooten]

See this example code for dynamically creating other kinds of preferences: developer.android.com/resources/samples/ApiDemos/src/com/…

[Greg Dan]

findPreference should work instead of findViewById. However findPreference is deprecated in Honeycomb.

[Malachi]

A little strange that getEntries and getEntryValues are DOA but I'm sure there's a good reason. And this is a great solution.

[Jeff G]

Boris - your link doesn't work: it just takes me to the Download Samples index. However, I followed the path indicated when hovering over your link in my downloaded samples and found it. (For anyone else: start from android-sdk\samples\android-<version>\ApiDemos then follow the rest of Boris's path)

[Warpzit]

Samples path: sdk\samples\android-21\legacy\ApiDemos\src\com\example\andro‌​id\apis\preference