getStringArrayExtra() always return null

Question

I am trying to open new Google map activity from my main activity, I pass the Extras in the main activity and check the intent everything is fine and all the information is there.When the new activity opens, if I check the information using the debug I can see that everything is fine too yet, when I am using getStringArrayExtra() it always returns NULL.

Main Activity

mapIntent.putExtra("LAN_LIST", goodLan.toArray());
mapIntent.putExtra("LON_LIST", goodLon.toArray());
mapIntent.putExtra("HeadLine_LIST", goodheadline.toArray());
mapIntent.putExtra("Context_LIST", goodcontext.toArray());
startActivity(mapIntent);

Map Activity

    Intent intent = getIntent();

    lan = intent.getExtras().getStringArray("LAN_LIST");//does not work
    lan = intent.getStringArrayExtra("LAN_LIST");//does not work too
    lon = intent.getStringArrayExtra("LON_LIST");//same
    Headline = intent.getStringArrayExtra("HeadLine_LIST");//same
    Context = intent.getStringArrayExtra("Context_LIST");//same

I am not posting the log because I don't have any exceptions, all the variables get null and that it.

Thank you!

Answer 1

When you are setting the value as array you could try like this for all:

mapIntent.putExtra("LAN_LIST", goodLan.toArray(new String[goodLan.size()]));

Assuming the Lists contain only Strings, this will work.

Alternately, in your MainActivity you could pass them as ArrayList using

mapIntent.putStringArrayListExtra("LAN_LIST", (ArrayList<String>) goodLan);

And then you could receive them at MapActivity as intent.getExtras().getStringArrayListExtra("LAN_LIST");

Answer 2

我所要做的就是将信息作为List传递。

Answer 3

您还必须添加activity的名称作为方法getStringArray的参数。

 lan = intent.getExtras().getStringArray(MainActivity.LAN_LIST);