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POupdate TextView in fragment A when clicking button in fragment B
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  1. POupdate TextView in fragment A when clicking button in fragment B
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    copied!<p>I have two fragments sitting side by side in the same activity. When I touch a button in the right fragment (fragment B), I need a TextView in the left fragment to update (fragment A). I have looked all over for the best way to do this, but nothing seems to work for my needs. Could someone possibly give me an example of how I would code this? Fragment A is set through the XML layout, and fragment B gets loaded programmatically into a container. I have tried accomplishing this by using a method in fragment A to update the text, and calling on that method from a method in the parent activity. I then call on the method in the parent activity from fragment B.</p> <p>This is the code in fragment B that declares the interface and calls a method in the interface</p> <pre><code>AttackCards attackCards; public interface AttackCards { public void deckSize(); } public void onAttach(DeckBuilder deckBuilder) { super.onAttach(deckBuilder); attackCards = (AttackCards) deckBuilder; } attackCards.deckSize(); //this is in my onclick methods </code></pre> <p>This is the code in the activity that implements the interface and calls the method in fragment A</p> <pre><code>public class DeckBuilder extends Activity implements AttackCards{ public void deckSize() { DeckBuilderFragment deckBuilderFragment = (DeckBuilderFragment)getFragmentManager(). findFragmentById(R.id.deckbuilder_fragment); deckBuilderFragment.deckSize(); } </code></pre> <p>This is the method in fragment A that appends the textview with the contents of a shared preferences value</p> <pre><code>public void deckSize() { deckSize = (TextView) getView().findViewById(R.id.decksize); final SharedPreferences defaultDeck = getActivity() .getSharedPreferences("defaultDeck", Context.MODE_PRIVATE); deckSize.setText(String.valueOf(defaultDeck.getInt("decksize", 0))); } </code></pre> <p>Sadly this attempt simply brings me a nullpointer when touching a button. I am getting a null pointer at</p> <pre><code>attackCards.deckSize(); //this is in my onclick methods </code></pre> <p>Could someone please help me out with an example of how to do this correctly?</p>
 

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