Develop Reference

Set and call Fragment Tag correct

Can't get rid of this problem. I saw a couple other questions with a similar problem, but nothing fixed it.
Short story: I replace my placeholders with fragments in my MainActivty and would like to call a public method from that new fragment. But calling the fragment from his Tag, leads to a "Null object reference" error.
I tried multiple ways to set and call the Tag but without success
Main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/mainActivity"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:orientation="vertical"
app:menu="#menu/quick_settings"
tools:context="....">
<ScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/scrollView">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:id="#+id/fragment1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" />
<LinearLayout
android:id="#+id/fragment2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" />
<LinearLayout
android:id="#+id/fragment3"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" />
...
Main.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_annual_service);
createList();
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
private void createList() {
Resources r = getResources();
String packageName = getPackageName();
//Array with all Fragments
fragmentList = new Fragment[]{
new FragmentA,
new FragmentB,
new FragmentC,
...
};
numberOfFragments = fragmentList.length;
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
for (int arrayIndex=0, fragmentNumber=1; fragmentNumber <= numberOfFragments; arrayIndex++, fragmentNumber++){
fragmentTransaction.replace(r.getIdentifier("fragment" + fragmentNumber, "id", packageName), fragmentList[arrayIndex], "fragment0"+fragmentNumber); // also try to set the TagName
}
fragmentTransaction.commit();
fragmentManager.executePendingTransactions();
((Unfold)fragmentManager.findFragmentByTag("fragment01")).unfold(); // Method is implemented by a interface
FragmentA.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/FragmentA"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="#+id/content"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:paddingEnd="20dp"
android:paddingStart="45dp"
android:visibility="gone">
...
</LinearLayout>
FragmentA.java
Button backBtn;
TextView header;
LinearLayout llayout;
Drawable defaulBG;
View view;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return setListener(inflater, container);
}
private View setListener(LayoutInflater inflater, ViewGroup container){
view = inflater.inflate(R.layout.fragment_general_information, container, false);
header = (TextView) view.findViewById(R.id.generalInformationHeaderText);
header.setOnClickListener(this);
llayout = (LinearLayout) view.findViewById(R.id.content);
defaulBG = inForkliftBtn.getBackground();
backBtn = (Button) view.findViewById(R.id.backBtn);
setRetainInstance(true);
return view;
}
public void unfold(){
if(llayout.getVisibility() == View.GONE){
llayout.setVisibility(View.VISIBLE);
}else{
llayout.setVisibility(View.GONE);
}
}

Call executePendingTransactions() on fragment manager after committing transaction
...
fragmentTransaction.commit();
fragmentManager.executePendingTransactions();
((Unfold)fragmentManager.findFragmentByTag("fragment01")).unfold();
EDIT 1
You can try another option:
Do not add the executePendingTransactions()
In fragment's onViewCreated, if getTag() mathes "fragment01" call unfold method

Fragment is overlapping

I have created an app when i'm testing my app or i clicked on back button my fragment is overlapping other fragment. I don't know why it's happening. Please help me i need help..
My codes
public class MainActivity extends AppCompatActivity {
private SharedPreferences pref;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pref = getPreferences(0);
initFragment();
}
private void initFragment(){
Fragment fragment;
if(pref.getBoolean(Constants.IS_LOGGED_IN,false)){
fragment = new ProfileFragment();
}else {
fragment = new LoginFragment();
}
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.fragment_frame,fragment);
ft.commit();
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
android:background="#ff51b46d"
tools:context="com.example.hldev.docup.MainActivity">
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.hldev.docup.MainActivity">
<FrameLayout
android:id="#+id/fragment_frame"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
</android.support.design.widget.CoordinatorLayout>
Uploads.java
public class Uploads extends Fragment implements View.OnClickListener{
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view=inflater.inflate(R.layout.activity_uploads, container, false);
ivAttachment = (ImageView)view.findViewById(R.id.ivAttachment);
tv_name = (TextView)view.findViewById(R.id.tv_name);
tv_email = (TextView)view.findViewById(R.id.tv_email);
bUpload = (Button)view.findViewById(R.id.b_upload);
tvFileName = (TextView)view.findViewById(R.id.tv_file_name);
ivAttachment.setOnClickListener(this);
bUpload.setOnClickListener(this);
return view;
}
private void goToProfile(){
Fragment profile = new ProfileFragment();
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.fragment_frame,profile);
ft.commit();
}
}

Just set a background color to your new <fragment /> in XML file or else it will be transparent and show a replaced fragment.
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="schemas.android.com/apk/res/android";
xmlns:tools="schemas.android.com/tools";
android:id="#+id/frag24"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/green">
<!-- Your Content -->
</RelativeLayout>
</FrameLayout >

set white background color of your parent layout of your activity_uploads. also do same with all layout which you use in Fragment.

replace your code with below.
<RelativeLayout xmlns:android="schemas.android.com/apk/res/android"
xmlns:tools="schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:background="#android:color/holo_green_dark"
tools:context="com.example.hldev.docup.Uploads">

ViewPager image gallery inside a Fragment

Hello im new android developer and i try to do the next things with no success
i have Activity, inside the activity i have fragment and inside it i have ** view pager image galley**.
the problem is when i run the app with the activity with the fragment and and gallery inside it the app crash
but when i tried to run the activity with the gallery and the fragment separately they works fine
whats the problem?
here my code:
Activity
public class infoActivity extends AppCompatActivity {
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.hotel_info);
}
}
Activity XML
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:weightSum="1">
<fragment
android:layout_width="match_parent"
android:layout_height="200dp"
android:name="co.checkit.mobile.checkit.Model.gallery_fragment"
tools:layout="#layout/imagegalleryfragment"
android:id="#+id/fragmentid" />
</LinearLayout>
ass you can see i set the fragment inside the activity
Fragment class
public class Hotelsgallery_fragment extends Fragment {
ImageAdapter adapter;
ViewPager viewPager;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View myFragmentView = inflater.inflate(R.layout.imagegalleryfragment, container, false);
viewPager = (ViewPager)myFragmentView.findViewById(R.id.viewpager);
adapter = new ImageAdapter(this);
viewPager.setAdapter(adapter);
return myFragmentView;
}
}
i set the gallery inside the fragment class
Fragment XML
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<android.support.v4.view.ViewPager
android:layout_width="match_parent"
android:layout_height="200dp"
android:id="#+id/viewpager">
</android.support.v4.view.ViewPager>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Large Text"
android:id="#+id/textView4"
android:layout_gravity="center_horizontal" />
</LinearLayout>

instead of putting fragment inside xml, put frame layout
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:weightSum="1">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="200dp"
android:id="#+id/frame_layout_id" />
</LinearLayout>
create fragment inside a activity, inflate using frame layout id
YourFragment fragment = new YourFragment();
FragmentTransaction ft = getSupportFragmentManager()
.beginTransaction();
ft.add(R.id.frame_layout_id, fragment);
ft.commit();

Simple fragement is not working

I am practicing to multi-pane screen using fragment, but it's not working properly. I want two frame in single activity. One should be static and another will dynamic list.
main_biddingwindow.xml
<?xml version="1.0" encoding="utf-8"?>
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:minWidth="200dp"
android:weightSum="1"
android:id="#+id/ag">
<fragment
android:layout_width="163dp"
android:layout_height="match_parent"
android:name="driver.project_detail"
android:id="#+id/fragment"
android:layout_row="0"
android:layout_column="0" />
<fragment
android:layout_width="184dp"
android:layout_height="match_parent"
android:name="driver.bid_list"
android:id="#+id/fragment2"
android:layout_row="0"
android:layout_column="19" />
</GridLayout>`
main.class
public class biddingWindow extends Activity{
protected void OnCreate(Bundle b){
super.onCreate(b);
setContentView(R.layout.main_biddingwindow);
}
}
bidlist.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/listView"
android:layout_gravity="center_horizontal"
/>
</LinearLayout>
bid_list.java
public class bid_list extends Fragment {
public View onCreateView(LayoutInflater inflater ,ViewGroup container ,Bundle s){
return inflater.inflate(R.layout.bidlist,container, false);
}
}
output screen

Just Create the objects of both the fragments in activity and you can access everything in fragment
public class bid_list extends Fragment {
public ListView listView;
public View onCreateView(LayoutInflater inflater ,ViewGroup container ,Bundle s){
View view = inflater.inflate(R.layout.bidlist,container, false);
listView = (ListView)view.findViewById(R.id.listView);
return view ;
}
}

public class bid_list extends Fragment {
public ListView listView;
public View onCreateView(LayoutInflater inflater ,ViewGroup container ,Bundle s){
View view = inflater.inflate(R.layout.bidlist,container, false);
listView = (ListView)view.findViewById(R.id.listView);
return view ;
}
}
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/ag">
<FrameLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:name="driver.project_detail"
android:id="#+id/fragment"/>
<FrameLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="2"
android:name="driver.bid_list"
android:id="#+id/fragment2"/>
</LinearLayout>
class Main extends Activity
{
protected void OnCreate(Bundle b){
super.onCreate(b);
setContentView(R.layout.main_biddingwindow);
FrameLayout frame1 = (FrameLayout)findViewById(R.id.fragment);
FrameLayout frame2 = (FrameLayout)findViewById(R.id.fragment);
Fragment1 fragment1 = new Fragment1();
Fragment2 fragment2 = new Fragment2();
frame1.removeAllView();
frame1.addView(fragment1)
frame2.removeAllView();
frame2.addView(fragment2)
}
}

App crashes after adding Toolbar to a Fragment

I'm trying to switch from an Activity with a fragment without a Toolbar (R.id.main_screen) to one that has a Toolbar (R.id.source_items_list).
However, whenever I have a Toolbar in R.id.source_items_list, it crashes. The error I'm getting is
android.view.InflateException: Binary XML file line #10: Error
inflating class android.support.v7.widget.Toolbar
which comes from the line
View view = inflater.inflate(R.layout.fragment_sourceitem_list, viewGroup, false); in the following code.
I wonder what I'm doing wrong. Here's my code.
public class MainActivity extends FragmentActivity implements MainFragment.OnFragmentInteractionListener {
...
#Override
protected void onCreate(Bundle savedInstanceState) {
requestWindowFeature(Window.FEATURE_NO_TITLE);
super.onCreate(savedInstanceState);
// set uncaught exception handler for thread
// Thread.setDefaultUncaughtExceptionHandler(new ExceptionHandler(this));
setContentView(R.layout.activity_main);
FragmentManager fragmentManager = getSupportFragmentManager();
mMainFrame = MainFragment.newInstance();
fragmentManager.beginTransaction().add(R.id.container, mMainFrame).commit();
}
#Override
public void onFragmentInteraction(int id) {
FragmentManager fragmentManager = getSupportFragmentManager();
switch (id) {
case R.id.button_sources:
Fragment fragment = new SourceListFragment();
FragmentTransaction fragmentTrans = fragmentManager.beginTransaction();
fragmentTrans.replace(R.id.container, fragment);
fragmentTrans.addToBackStack(null);
fragmentTrans.commit();
break;
default:
break;
}
}
}
public class SourceListFragment extends Fragment implements AbsListView.OnClickListener {
...
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup viewGroup, Bundle savedInstanceState) {
Log.d("SOURCELIST", "SourceListFragment onCreateView\n");
View view = inflater.inflate(R.layout.fragment_sourceitem_list, viewGroup, false);
return view;
}
public static SourceListFragment newInstance(BluetoothAdapter adapter) {
SourceListFragment fragment = new SourceListFragment();
mBTAdapter = adapter;
return fragment;
}
// Container Activity must implement this interface
public interface OnFragmentInteractionListener {
public void onFragmentInteraction(int id);
}
}
Here's the layout:
activity_main.xml:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:materialdesign="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FFF"
android:orientation="vertical"
android:id="#+id/container">
</FrameLayout>
fragment_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/main_screen"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="148dp">
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="128dp"
android:background="#01579b"
android:paddingBottom="20dp"
android:paddingLeft="104dp" android:id="#+id/banner">
</RelativeLayout>
</RelativeLayout>
<android.support.percent.PercentRelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/button_sources"
app:layout_widthPercent="30%"
app:layout_heightPercent="30%"
app:layout_marginTopPercent="10%"
app:layout_marginLeftPercent="15%"
app:layout_marginRightPercent="5%"/>
...
</android.support.percent.PercentRelativeLayout>
</LinearLayout>
fragment_sourceitem_list.xml:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:id="#+id/source_items_list"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v7.widget.Toolbar
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/toolbar"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
android:background="?attr/colorPrimary"/>
<ListView android:id="#android:id/list" android:layout_width="match_parent"
android:layout_height="match_parent"
/>
<com.gc.materialdesign.views.ProgressBarCircularIndeterminate
android:id="#+id/progressBarCircularIndeterminate"
android:layout_width="32dp"
android:layout_height="32dp"
android:background="#1E88E5" />
</FrameLayout>
Any help will be appreciated.
Thanks