I'm trying to do this: http://android-er.blogspot.com/2012/06/communication-between-fragments-in.html Except that I'm using a FragmentStatePagerAdapter
I have an Activity with two fragments(FragmentA & FragmentB)
FragmentA has an edittext and a button, FragmentB has a textview
Now all I want is that whenever I enter something in the edittext and click the button, that something will appear on my textview.
MainActivity:
public class MainActivity extends FragmentActivity {
ViewPager viewPager = null;
String TabFragmentB;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewPager = (ViewPager)findViewById(R.id.pager);
FragmentManager fragmentManager = getSupportFragmentManager();
viewPager.setAdapter(new MyAdapter(fragmentManager));
}
public class MyAdapter extends FragmentStatePagerAdapter {
public MyAdapter (FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int i) {
Fragment fragment = null;
if (i == 0)
{
fragment = new FragmentA();
}
if (i == 1)
{
fragment = new FragmentB();
}
return fragment;
}
@Override
public int getCount() {
return 2;
}
}
public void setTabFragmentB(String t) {
TabFragmentB = t;
}
public String getTabFragmentB() {
return TabFragmentB;
}
}
FragmentA:
public class FragmentA extends Fragment {
EditText et;
Button bt;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fraga, container, false);
et = (EditText)v.findViewById(R.id.edit1);
bt = (Button)v.findViewById(R.id.button1);
bt.setOnClickListener(Click);
return v;
}
OnClickListener Click = new OnClickListener(){
@Override
public void onClick(View v) {
String textPassToB = et.getText().toString();
String TabOfFragmentB = ((MainActivity)getActivity()).getTabFragmentB();
FragmentB fragmentB = (FragmentB)getActivity()
.getSupportFragmentManager()
.findFragmentByTag(TabOfFragmentB);
fragmentB.updateText(textPassToB);
}
};
}
FragmentB:
public class FragmentB extends Fragment {
TextView tv;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragb, container, false);
tv = (TextView)v.findViewById(R.id.text1);
String myTag = getTag();
((MainActivity)getActivity()).setTabFragmentB(myTag);
return v;
}
public void updateText(String t){
tv.setText(t);
}
}
LogCat:
FATAL EXCEPTION: main
java.lang.NullPointerException
at lmf.sample1.FragmentA$1.onClick(FragmentA.java:43)
at android.view.View.performClick(View.java:4212)
at android.view.View$PerformClick.run(View.java:17476)
at android.os.Handler.handleCallback(Handler.java:800)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5371)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)
Whenever I click the button on my first fragment, my app crashes. What the hell is the problem?
Steps to do:
First, create some class to represent event when your text changes:
public class TextChangedEvent {
public String newText;
public TextChangedEvent(String newText) {
this.newText = newText;
}
}
Then, in fragment A:
//when text changes
EventBus bus = EventBus.getDefault();
bus.post(new TextChangedEvent(newText));
in fragment B:
EventBus bus = EventBus.getDefault();
//Register to EventBus
@Override
public void onCreate(SavedInstanceState savedState) {
bus.register(this);
}
//catch Event from fragment A
public void onEvent(TextChangedEvent event) {
yourTextView.setText(event.newText);
}