In my Android app I'm replacing a Fragment passing an int as argument:
Bundle bundle = new Bundle();
MyFragment fragment = new MyFragment ();
FragmentTransaction ft = getActivity().getSupportFragmentManager().beginTransaction();
bundle.putInt("id", myId);
fragment.setArguments(bundle);
ft.addToBackStack(null).replace(R.id.placeholder, fragment).commit();
Inside MyFragment, I'm checking if this Bundle is null:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_my, container, false);
Bundle args = this.getArguments();
if(args != null) {
Log.d(TAG, "args: "+args);
}
else {
Log.d(TAG, "no args: "+args);
}
return v;
}
My Logcat result:
args: Bundle[{id=1}]
no args: null
Why both if and else are executing?
Why both if and else are executing?
they are probably two different transactions. One that you committed programmatically, the other is probably declared in the layout of hosting activity
Related
I want to pass data from my Activity to a Fragment. I have no idea how to do it. I've seen many solutions but no one of them did really work.
I just want to pass a simple String to the Fragment.
I have tried it this way:
public class PhotoActivty extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_photo);
if (null == savedInstanceState) {
Bundle bundle = new Bundle();
String myMessage = "Stackoverflow is cool!";
bundle.putString("message", myMessage );
BasicFragment fragInfo = new BasicFragment();
fragInfo.setArguments(bundle);
android.app.FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.photo_frame, fragInfo);
transaction.commit();
}
}
}
What is the error there? I call it this way:
String myValue = this.getArguments().getString("message");
In the onCreateView in the Fragment
I usually use a static factory pattern:
public class MyFragment extends Fragment {
public static MyFragment newInstance(int index) {
MyFragment f = new MyFragment();
Bundle args = new Bundle();
args.putInt("index", index);
f.setArguments(args);
return f;
}
}
When you create the fragment in your Activity:
Fragment MyFragment = MyFragment.newInstance(5);
Alex Lockwood has a good rundown on why this is a preferred design pattern:
http://www.androiddesignpatterns.com/2012/05/using-newinstance-to-instantiate.html
Bundle bundle = new Bundle();
String myMessage = "Stackoverflow is cool!";
bundle.putString("message", myMessage );
Fragment fragInfo = new BasicFragment();
fragInfo.setArguments(bundle);
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.photo_frame, fragInfo);
transaction.commit();
try this inside your if
from activity:
Bundle bundleObject = new Bundle();
bundleObject.putString("data", " Send From Activity");
/*set Fragmentclass Arguments*/
Fragment fragmentobject = new Fragment();
fragmentobject .setArguments(bundleObject );
From Fragment You receive this way:
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
String stringText = getArguments().getString("data");
return inflater.inflate(R.layout.fragment, container, false);
Not sure if this is the real cause of the problem, but you have to use getSupportFragmentManager() instead of getFragmentManager() inside AppCompatActivity. Also, classes such as Fragment and FragmentTransaction should come from support.v4 package.
Remove if (null == savedInstanceState) in your activity. If savedInstanceStatenull == null then BasicFragment will not replace your FrameLayout for R.id.photo_frame.
I am using Bundle to passing data from my First TabFragment but it prompts out with the NullPointerException. Error is occur when getArguments() in list_fragments2 in second tab
MainActivity Fragment
list_fragment2 fragment = new list_fragment2();
Bundle b = new Bundle();
b.putString("test","text");
fragment.setArguments(b);
Toast.makeText(this, "" + b, Toast.LENGTH_SHORT).show();
SecondActivity Fragment
public class list_fragment2 extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View h = inflater.inflate(R.layout.tab2, container, false);
TextView textView = (TextView) h.findViewById(R.id.textView);
Bundle bundle=getArguments();
//your string
if(bundle != null) {
String test = bundle.getString("test");
textView.setText(test);
}
return h;
}
}
Do you actually load your second fragment?
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
list_fragment2 fragment = new list_fragment2();
Bundle b = new Bundle();
b.putString("test","text");
fragment.setArguments(b);
fragmentTransaction.replace(placeholder, fragment);
fragmentTransaction.commit();
I think you can create your instance of list_fragment2 code within list_fragment2. Maybe your codes recreated list_fragment2 many times.
public static list_fragment2 createInstance() {
list_fragment2 fragment = new list_fragment2();
Bundle bundle = new Bundle();
bundle .putString("test","text");
fragment.setArguments(bundle);
return fragment;
}
I'm working on an app I need to send some data from ListFragment to ItemFragment. I use bundle but I get nullpointerexception. I should mention that i'm a newbie and this is my first app. so let me know if what I did is wrong or confusing. Here are my codes
ListFragment.java
if (child != null && mGestureDetector.onTouchEvent(motionEvent)) {
int position = recyclerView.getChildLayoutPosition(child);
selectedItem = mItems.get(position);
itemId = mItems.get(position).getId();
openFragment(new ItemFragment(), "MyApp");
ItemFragment if = new ItemFragment();
Bundle bundle = new Bundle();
bundle.putLong("selectedId", itemId);
if.setArguments(bundle);
}
return false;
}
ItemFragment.java
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
Bundle bundledData = this.getArguments();
selectedId = bundledData.getLong("selectedId");//here is the line 105 in logcat
return mRootView;
}
Logcat
java.lang.NullPointerException
at me.myapp.fragments.ItemFragment.onCreateView(ItemFragment.java:105)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:517)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
---Added---
For some reason, I still get the same error when I tried the answers here except for nguyen's. From what I understand in nguyen's code, I use this
ListFragment.java
private long itemId;
if (child != null && mGestureDetector.onTouchEvent(motionEvent)) {
int position = recyclerView.getChildLayoutPosition(child);
selectedItem = mItems.get(position);
itemId = mItems.get(position).getId();
Bundle bundle = new Bundle();
bundle.putLong("selectedId", itemId);
ItemFragment itemFrag = ItemFragment.newInstance(bundle);
openFragment(new ItemFragment(), "Update Item");
Toast.makeText(getActivity(), "id = " + itemId, Toast.LENGTH_SHORT).show();
ItemFragment.java
private long selId;
public static ItemFragment newInstance(Bundle bundle) {
ItemFragment frag = new ItemFragment();
frag.setArguments(bundle);
return frag;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
if (getArguments() != null) {
selId = getArguments().getLong("selectedId");
}
makeToast(""+selId);
return mRootView;
}
I didn't get any error with these codes. The toast in ListFragment does shows the correct value but the toast in ItemFragment always returns 0. what am i missing here??
To put bundle in Fragment you should use a static funtion newInstance(Bundle bundle) in your ItemFragment:
public static ItemFragment newInstance(Bundle bundle) {
ItemFragment myFragment = new ItemFragment();
myFragment.setArguments(bundle);
return myFragment;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Bundle bundle = getArguments();
// DO SOMETHING
return super.onCreateView(inflater, container, savedInstanceState);
}
And use it you call:
Bundle bundle = new Bundle();
//put data in bundle
ItemFragment itemfrag = ItemFragment.newInstance(bundle);
In ItemFragment, you should write in this way
Bundle bundledData = this.getArguments();
if (getArguments() != null) {
selectedId = bundledData.getLong("selectedId");
}
And you may add Toast inside the if block to check whether the selectedId get displayed or not.
Edited
ItemFragment.java
private long selId;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View edit_details = inflater.inflate(R.layout.edit_staff_list, container, false);
Bundle bundle = this.getArguments();
if (getArguments() != null) {
selId = bundle.getLong("selectedId");
Toast.makeText(getActivity(), selId, Toast.LENGTH_LONG).show();
}
Try edit your code in listFragment to this.
if (child != null && mGestureDetector.onTouchEvent(motionEvent)) {
int position = recyclerView.getChildLayoutPosition(child);
selectedItem = mItems.get(position);
itemId = mItems.get(position).getId();
ItemFragment itemFragment = new ItemFragment();
Bundle bundle = new Bundle();
bundle.putLong("selectedId", itemId);
itemFragment.setArguments(bundle);
openFragment(itemFragment, "MyApp");
}
return false;
The problem with your code is you passed in a new instance of ItemFragment to openFragment() function instead of the one you created and added with a bundle.
You are creating two instances of the same fragment, setting the arguments on the second one, and showing the first one which doesn't have any arguments. Hence, the NullPointerException when you try to extract argument in onCreateView.
...
openFragment(new ItemFragment(), "MyApp"); // Show first fragment
ItemFragment if = new ItemFragment(); // Instantiate second fragment
Bundle bundle = new Bundle();
bundle.putLong("selectedId", itemId);
if.setArguments(bundle); // arguments go to the second one | The one which is never even displayed to the user.
...
After hours messing around with the code, trial and error, tried different codes, nguyen's code and the code here https://stackoverflow.com/a/16036693/5563156 gives me the idea. these codes seems to get the job done
ListFragment.java
mRecyclerView.addOnItemTouchListener(new RecyclerView.OnItemTouchListener() {
#Override
public boolean onInterceptTouchEvent(RecyclerView recyclerView, MotionEvent motionEvent) {
View child = recyclerView.findChildViewUnder(motionEvent.getX(), motionEvent.getY());
if (child != null && mGestureDetector.onTouchEvent(motionEvent)) {
int position = recyclerView.getChildLayoutPosition(child);
selectedItem = mItems.get(position);
itemId = mItems.get(position).getId();
//pass selected item's ID to Main Activity
Intent i = new Intent(getActivity(), MainActivity.class);
i.putExtra("selectedId", itemId);
startActivity(i);
Toast.makeText(getActivity(), "id = " + itemId, Toast.LENGTH_SHORT).show();
}
return false;
}
In MainActivity's OnCreate
if(savedInstanceState == null){
//receives selected item's ID passed from ListFragment
Intent intent = getIntent();
long selId = intent.getLongExtra("selectedId", 0);
if (selId > 0) {
//send the selected item ID to ItemFragment
Bundle bundle = new Bundle();
bundle.putLong("selectedId", 0);
ItemFragment frag = new ItemFragment();
openFragment(ItemFragment.newInstance(selId), "Update Item");
frag.setArguments(bundle);
}}
ItemFragment.java
public static ItemFragment newInstance(long selId) {
ItemFragment fragment = new ItemFragment();
if (selId > 0) {
Bundle bundle = new Bundle();
bundle.putLong("selectedId", selId);
fragment.setArguments(bundle);
}
return fragment;
}
In ItemFragment's OnCreateView
Bundle args = getArguments();
if (args != null && args.containsKey("selectedId")) {
selId = args.getLong("selectedId");
}
Thanks to everyone who posted their codes! Appreciate the help.
I have two fragments and FilterFragment and LocationListFragment. when I am switching to LocationListFragment.java I am getting values in getArguments() and from LocationListFragment.java to FilterFragment.java getting null values by calling getArgument(); here is the details
In FilterFargment.java code is here for set values:
LocationListFragment locationListFragment = new LocationListFragment();
bundle = new Bundle();
Log.e("",""+locationList.getLocationListFilter().size());
bundle.putParcelable(Constant.LOCATION_LIST_FILTER, locationList);
bundle.putString(Constant.FROM_DATE_FILTER, textView_time_from.getText().toString());
locationListFragment.setArguments(bundle);
((DashbordActivity) getActivity()).switchFragment(locationListFragment, true);
In LocationListFragment.java (getting values)
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle args = getArguments();
if (args != null) {
locationList = args.getParcelable(Constant.LOCATION_LIST_FILTER);
getFromDate = args.getString(Constant.FROM_DATE_FILTER);}}
And here from LocationListFragment on button click send data to FilterFragment sending new values with bundle:
FilterFragment filterFragment =new FilterFragment();//.newInstance(getFromDate, getEndDate, getLocation, getCategories);
Bundle bundle = new Bundle();
bundle.putString(Constant.FROM_DATE_FILTER, getFromDate);
bundle.putString(Constant.WHERE_FILTER, getLocation);
filterFragment.setArguments(bundle);
((DashbordActivity) getActivity()).switchFragment(filterFragment, true);
and in FilterFragment.java while returning back getting null value for getArguments(); code is here:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.fragment_filter, container, false);
Log.e("FilterFragment", "oncreateview");
Bundle args = getArguments();
Log.e("getArguments", "" + getArguments());//getting null here
Also, I have used this method for switching fragment,
public void switchFragment(BaseFragment fragment, boolean keep) {
FragmentManager manager = getSupportFragmentManager();
boolean fragmentPopped = manager.popBackStackImmediate(fragment.getClass().getSimpleName(), 0);
if (!fragmentPopped && manager.findFragmentByTag(fragment.getClass().getSimpleName()) == null) { //fragment not in back stack, create it.
FragmentTransaction tr = manager.beginTransaction();
tr.replace(R.id.container, fragment, fragment.getClass().getSimpleName());
if (keep) {
tr.addToBackStack(fragment.getClass().getSimpleName());
Log.e("keep", "BaseAct:" + keep);
}
tr.commit();
}
}
Can you tell me what I am missing? Any help will be appreciated.
Example
I do not understand this example.
How to apply in my program
I try to write In my program
General use that I can.
But replaced fragment.
I do not know how to use.
Pass the value of the object.
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.templistmune, container, false);
FragmentManager DS2 = getFragmentManager();
FragmentTransaction DSE2 = DS2.beginTransaction();
Fragment DF2 = DS2.findFragmentById(R.id.frameLayout4);
if (DF2 == null) {
String title = "Fragment A";
templistview2 usermune = new templistview2(title);
DSE2.add(R.id.frameLayout4, usermune);
DSE2.addToBackStack(null);
DSE2.commit();
/////////////////////////////////////////////////////////
Bundle bundle = new Bundle();
String SAS="50";
bundle.putString("ST", SAS);
DF2.setArguments(bundle);
////////////////////////////////////////////////
}
The pick value the object
templistview2.java
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.templistmune2, container, false);
////////////////////////////////////////////////////////////////////////////////////
Bundle bundle = this.getArguments();
String myST = bundle.getString("ST", SAS);
///////////////////Error SAS cannot be resolved to a variable /////////////////
return view;
}
You're only adding adding the Bundle when DF2 is null... so your program will either crash with a NullPointerException somewhere along the line or run but not have the Bundle passed.
So place
Bundle bundle = new Bundle();
String SAS="50";
bundle.putString("ST", SAS);
DF2.setArguments(bundle);
outside the if structure.