存储一个活动的意图，但是开始另一个活动

Question

I am new to android and I have a problem. I want to store intent for an activity but start a different activity. I have a backgroundworker activity that has to store intent for postAnnotationActivity, but has to start InstructionsActivity. If I use intentID.getStringExtra in PostAnnotationActivity then the output = null . Can somebody help?

Part of code from Backgroundworker:

        Intent intent = new Intent(context, InstructionsActivity.class);
        Intent intentID = new Intent(context, PostAnnotationsActivity.class);
        intentID.putExtra(ID, id);
        context.startActivity(intent);

part of PostAnnotationActivity:

    Intent intentID = getIntent();
    String getID = intentID.getStringExtra(BackgroundWorker.ID);

From InstructionsActivity I'll go to StartActivty using startActivity(new Intent(this, ShowPaintingActivity.class) and then to PostAnnotationActivity using startActivity(new Intent(this, PostAnnotationsActivity.class));

Answer 1

Modify your code as following:

In Backgroundworker:

 Intent intentID = new Intent(context, InstructionsActivity.class);
 intentID.putExtra("ID", id);
 context.startActivity(intentID);

In InstructionsActivity:

 Intent intentID = getIntent();
 String getID = intentID.getStringExtra("ID");

 Intent intent = new Intent(context, ShowPaintingActivity.class);
 intent.putExtra("ID", getID);
 context.startActivity(intent);

In ShowPaintingActivity:

 Intent intentID = getIntent();
 String getID = intentID.getStringExtra("ID");

 Intent intent = new Intent(context, PostAnnotationActivity.class);
 intent.putExtra("ID", getID);
 context.startActivity(intent);

In PostAnnotationActivity:

Intent intentID = getIntent();
String getID = intentID.getStringExtra("ID");

And another better solution is, as user1375469 suggested, you can save value to preferences in Backgroundworker and then retrieve it from PostAnnotation Activity.

Answer 2

Try storing your Intent instead as a string and use shared preferences to store/retrieve your Intent. Like so.

    SharedPreferences prefs = this.getSharedPreferences("myPrefsKey", Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = prefs.edit();

    editor.putString("StoredIntent", "String you want to store here");
    editor.commit();

Answer 3

Your are getting the output null because you are not starting the Activity ie

 context.startActivity(intentID);  

while you are passing the data into it..
and you want to go to my InstuctionsActivity but already store some data from BackgroundWorker for PostAnnotationActivity....
So, you have to use SharedPreference for this purpose....