Java：向不同的活动发送意图

Question

I'm creating a google maps application and I need to send over ALL the information of the markers which the user has created. However, i do not want to open the activity afterwards, only send the data and then open the activity through a separate button. Any suggestions to how i should approach this issue?

here is the code where the marker is created, and sent over to the other activity, but i don't want to start the activity that is receiving the info :(

@Override
protected void onActivityResult(int requestCode, int resultCode,
                                Intent data) {
    if (requestCode == GET_DETAILS) {
        if (resultCode == RESULT_OK) {
            List<MarkerOptions> markers = new ArrayList<MarkerOptions>();

            String marker_title=data.getStringExtra("title");

            MarkerOptions markerOptions = new MarkerOptions()
                    .position(new LatLng(lat, lon))
                    .title(marker_title);
            Marker m = mMap.addMarker(markerOptions);
            markers.add(markerOptions);

            MarkerOptions[] markersArray = markers.toArray(new MarkerOptions[markers.size()]);
            Intent intent = new Intent(this, MarkerListActivity.class);
            intent.putExtra("markers", markersArray);
            startActivity(intent);

            mMap.moveCamera(CameraUpdateFactory.newLatLng(new LatLng(lat, lon)));

        }
    }
}

Also, another thing, what does the code:

List<MarkerOptions> markers = new ArrayList<MarkerOptions>();

do? I'm new to java and programming so I'm unsure why there are TWO data structures rather than one.

Answer 1

I think you are not getting what is the point of Intents for this case. Intents are used to start one Activity from another (among other things). As you say, you can pass data to the Activity that is about to be started in the Intent if the data is going to be needed by the Activity that is about to start. It seems to me that you want to send the data to the Activity via the Intent so every Activity instance of that class gets that data. It does not work that way. The data you send via the Intent is not "saved" for all instances of the Activity , so starting a new Activity via a Button at a later time, will not be able to access the data that was sent on a previous Intent .

In short, it seems that the Intent mechanism is not what you want for what you are trying to do. It looks like you want the Marker to be persisted in a SharedPreference or a Database , so then every instance of any Activity can get the data.