Question

I have 2 Tabs – Tab1 and Tab2, Tab1Activity and Tab2Activity.
I want to pass values from Tab1Actvity to Tab2Activity but dont want to start Tab2Activity.
When i try below code it gives null value:

In Tab1Activity

getParent().getIntent().putExtra("key", "value");

In Tab2Activity

String valueString=getParent().getIntent().getStringExtra("key");
System.out.println("Testing.....: "+valueString);

Answer 1

I really discourage you from using global variables by extending the Application class. If your application goes to the background, (e.g. due a phone call) the android system might decide to kill your application. When the call is finished your application and the activity stack will be restored, but your activity state will be lost.

I’d rather suggest you to use broadcasts to send data to another activity.

In your Tab1Activity:

Intent dataIntent = new Intent();
dataIntent.setAction("com.your.app.DATA_BROADCAST");
dataIntent.putExtra("tag", "your data");
sendBroadcast(dataIntent);

Tab2Activity:

BroadcastReceiver receiver = new BroadcastReceiver() {    
  @Override
  public void onReceive(Context context, Intent intent) {    
    String yourData = intent.getStringExtra("tag");
  }
};

IntentFilter filter = new IntentFilter();
filter.addAction("com.your.app.DATA_BROADCAST");
registerReceiver(receiver, filter);