go from activty A to B and come back to A android

I have read a lot but still havn't got my full answer. When starting app A,within onCreate method I get data from Api and set on ListVie开发者_开发百科w. Here also I have button and when I click to it I am going to Activity B and send some data. Within my B activity I send data to my api and if response status is ok I want to go back to activity A and reload data:call oncreate method in wich located my call function to api. In my manifest I have set

<activity android:name=".A" android:launchMode="singleInstance" ></activity>

but when I call startActivity:

Intent i = new Intent(B.this,A.class);
              Bundle b = new Bundle();
              String from = "upload";
              b.putString("action", from);
              startActivity(i);

I dont start activty A from point onCreate. I have already tried call finish() function after going to activity B but this doesn't get my any result. I want to append that in A activity I get file from gallery and pass uri to activity B.

Thanks.

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If you want to start a child activity with the intention of receiving a result, don't use startActivity(). Use startActivityForResult() instead. You will also need to implement (override) a method in your main activity to be called when the result is ready.

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If you want to get back to A and you need onCreate call finish() in A after startActivity(B). This way, onCreate will get called again when you go back to A (since it was destroyed).

Note that this is not a good way to handle things. A better method would be to move the "getting data from Api" part to onResume in activity A.

LATER EDIT: Indeed, startActivityForResult() is the way to go in this situation, no need to over-complicate things. Note to self: go for the easier route from now on.