Passing ArrayList with objects to new Activity?

问题:

I'm trying to pass an ArrayList from my first Activity to the next one. Basically, the first activity parses an XML file and creates an ArrayList with objects inside. What I want to do is send that ArrayList to my second activity and show some of the object data in a ListView.

I thought of doing this with an intent, but it looks like only primitive datatypes are usually passed through intents. Is this right?

If so, what would be a better solution to pass the data? Certainly Android must provide something to be able to do this kind of thing.

Any help/code examples are really appreciated..

Thanks

EDIT:

I solved this by first creating and calling the intent, and only parsing the XML in the Activity that I called. This way I didn't need to pass the objects anymore. But for those interested, you can read about how to pass data through activities, here.

回答1:

Complex types may be passed by means of Parcelable. An example is in this question:

Help with passing ArrayList and parcelable Activity

回答2:

I would do a toString on the array and pass it as an extra by doing a intent.putExtra("label". array.toString()); and then just recover it in the new activity.

回答3:

You can pass a String List using putStringArrayListExtra(String name, ArrayList<String> value) if it is strings. Or, you could serialize List and then use putExtra(String name, Serializable value).

If you don't want to/can't use the above, you could use a central util class with a static reference to the List. Just set it in your first Activity and get it in the second.

回答4:

This could be totally bad practice and I wouldn't know any better, but you could declare the ArrayList as public and static. Then just access it with Activity.ArraylistName.

回答5:

You can set the scope of ArrayList at application level or you can do this using parcelable.

回答6:

I made this trick to send from first Activity to second.

The first activity

ArrayList<String> mylist = new ArrayList<String>();  
Intent intent = new Intent(ActivityName.this, Second.class);
intent.putStringArrayListExtra("key", mylist);
startActivity(intent);

The second activity

To retrieve

ArrayList<String> list =  getIntent().getStringArrayListExtra("key");