How can I pass List as an Intent extra?

Question

I have a List that I want to convert into a String[] so that I can pass it as an extra with an intent.

List<String> votedBy = parseObject.getList("votedBy");

The intent logic:

Intent intent = new Intent(CommentActivity.this, UsersListActivity.class);
intent.putExtra(BundleConstants.KEY_LIST_TYPE, getString(R.string.voters));
intent.putExtra(BundleConstants.KEY_VOTERS_LIST, votedBy);
startActivity(intent);

My first thought was to convert the contents of the List to a String[], but that list is retrieved from a database and its size is not known apriori. One suggestion I had was to cast the votedBy List as Parcelable. I can't run the code at the moment so I'm not sure if that will work. What should I do here?

1

FYI: String is parcelable – Blackbelt Jan 12 '17 at 10:59

santosh kumar · Accepted Answer · 2017-01-12T11:07:05.830

8

This is used to send using intent from one activity.

            Intent intent = getIntent();
            intent.putStringArrayListExtra("votedBy",new ArrayList<>(votedBy));

To receive this can be used;

ArrayList<String> votedByList= getIntent().getStringArrayListExtra("votedBy");

edited Jan 12 '17 at 11:07

answered Jan 12 '17 at 11:01

santosh kumar

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And retrieve with ``bundle.getIntArray("BundleConstants.KEY_VOTERS_LIST")`` I take it? – Martin Erlic Jan 12 '17 at 11:06

score 1 · Answer 2 · answered Jan 12 '17 at 11:14

1

As far as I know, a List cannot be passed as an Intent extra.

I would suggest to pass the original String as was retrieved from the database, then parse it directly at the new activity (UserListActivity).

answered Jan 12 '17 at 11:14

MJim

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score 1 · Answer 3 · edited May 23 '17 at 11:53

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I think you should try with

List<String> list = ..;
String[] array = list.toArray(new String[0]);

as suggested in this question.
As you can see, the size of the list is never a problem for the conversion, you never need to know it.

edited May 23 '17 at 11:53

Community

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answered Jan 12 '17 at 11:18

SamCle88

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How can I pass List as an Intent extra?

3 Answers3