We Keep Coding

How to Load fragment when the app launches

I have created an app which basically has navigation drawer and I wish to load an fragment "home" whenever the activity launches instead of main activity.
Any idea how to do it.

You can call this method to view Fragments. In your case call this method on your onCreate()
//Fragment Changer
public void changeFragment(Fragment targetfragment) {
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.content_fragment, targetfragment, "fragment")
.setTransitionStyle(FragmentTransaction.TRANSIT_FRAGMENT_FADE)
.addToBackStack(null)
.commitAllowingStateLoss();
}
Example Usage
changeFragment(new YourFragment());

Basic solution can be implementing something like the below code in your onCreate method.
// get fragment manager
FragmentManager fm = getFragmentManager();
// replace
FragmentTransaction ft = fm.beginTransaction();
ft.replace(R.id.main_layout, new HomeFragment());
ft.commit();

Your Activity:
public class MainActivity extends AppCompatActivity {
public static final String TAG = MainActivity.class.getSimpleName();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
}
public String getHelloMessage() {
return "Hello!";
}
}
Your View:
public class MainView extends Fragment {
// Declarations
private Button testButton;
#Override
public View onCreateView(#NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.main_view, container, false);
// Getting the reference of controller from Application
MainController mainController = Application.getInstance().getMainController();
// Initializing view objects
testButton = view.findViewById(R.id.test_button);
// Setting actions
testButton.setOnClickListener(mainController.getTestAction());
return view;
}
// Reference to the view Object
public Button getTestButton() {
return testButton;
}
Your main_activity.xm lto connect the fragment
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/containerMainView"
android:layout_width="match_parent"
android:layout_height="match_parent">
<fragment
android:id="#+id/mainView"
android:name="com.template.views.MainView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</FrameLayout>
Your main_view.xml file your final view definition
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="#+id/test_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="#string/say_hello" />
</RelativeLayout>

In Android SDK/Java, how do I manipulate XML Views(imagebuttons, textviews) from a method in a fragment?

Solved! Thanks everyone for your help.
I am struggling with Fragments as a concept, and especially seem stuck on this one thing. What I'm trying to do is, using my fragment, manipulate its own layout's data. Every time I try to access an ImageButton from within the Fragment, it crashes the application. It works fine from the activity. Am I just misunderstanding Fragments fundamentally?
Code(cut down for size)-
This is the beginning of the activity my fragment is called from:
Display.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display);
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
MyFragmentClass MyFragment = new MyFragmentClass();
fragmentTransaction.add(R.id.fragment_container, MyFragment);
fragmentTransaction.commit();
The XML for that Activity:
activity_display.xml
<RelativeLayout 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:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context="com.mycompanyname.myprojectname.Display"
android:id="#+id/display_layout">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/fragment_container">
</FrameLayout>
</RelativeLayout>
The Fragment
MyFragmentClass.java
public class MyFragmentClass extends Fragment
{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_layout_screen, container, false);;
}
public void MethodTest()
{
}
}
The Fragment's XML file:
fragment_layout_screen.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:id="#+id/fragment_layout_screen"
tools:context="com.mycompanyname.myprojectname.MyFragmentClass">
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/my_button"
android:clickable="true"
android:onClick="buttonPress"
android:src="#drawable/button"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"/>
</RelativeLayout>
Basically I had all of this originally in Display.java, but wanted to add fragments, so I'm trying to move stuff out and into fragments, but I still need the ability to manipulate the xml info, I just can't.
From inside the Display.java activity I can easily call the ImageButton like this:
ImageButton myButton = (ImageButton) findViewById(R.id.my_button)
but if I do the same from MethodTest in the fragment, the app crashes.
I've searched many suggestions on here, trying various solutions from here: findViewById in Fragment but none of those seemed to work.
I've been reading through this for the setup: http://developer.android.com/guide/components/fragments.html and can't seem to find what I'm doing wrong.
Any help would be appreciated, and if you have any questions about my setup, please ask.

declare on fragment private View rootView;
On the onCreateView(...) set rootView = inflater.Inflate(..); and then access the imagebutton as ImageButton mButton =(ImageButton) rootView.findViewById(..);

Do like this in fragment
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.gridview, container, false);
GridView gridview = (GridView) view.findViewById(R.id.grid);
return view ;

Can't get fragment to show, no view found for id

I am trying to get a fragment to show that contains an EditText and a button. I am new to using fragments, so I am not sure exactly what the error message I get when trying to create the fragment means.
I have a class that extends Fragment, this is where the EditText and button are created.
public class EditNameFragment extends android.support.v4.app.Fragment {
EditText editText;
ImageButton button;
public EditNameFragment(){
}
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.edit_name_dialog, container, false);
editText = (EditText) view.findViewById(R.id.editTextDialog);
button = (ImageButton) view.findViewById(R.id.submitNewItemButtonDialog);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//stuff
}
});
return view;
}
Here is edit_name_dialog.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:id="#+id/edit_name_dialog"
>
<EditText
android:id="#+id/editTextDialog"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<ImageButton
android:id="#+id/submitNewItemButtonDialog"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
/>
</LinearLayout>
And here in my main activity (which must extend FragmentActivity because of another part) is where I try to set up my Fragment. I think it has something to do with what id I am referencing. I have seen some people using container classes when using fragments, but I do not understand why this is done.
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
EditNameFragment fragment = new EditNameFragment();
fragmentTransaction.add(R.id.edit_name_dialog, fragment, "tag");
fragmentTransaction.commit();
I get the error message when trying to run the code above
No view found for id 0x7f09002a (com.myapp:id/edit_name_dialog) for fragment EditNameFragment
If anyone could explain what I am missing here/ why people use container classes, that would be great. I know some people add fragments using XML, but I would like to do this only using java.
EDIT
I have added a class that extends FragmentActivity, following the model for a container class
public class EditNameFragmentActivity extends FragmentActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.edit_name_fragment_container);
}
}
Is the parameter for setContentView supposed to be the layout, or an id?
Here is the xml file that defines where the fragment should be
edit_name_fragment_container.xml
<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"
>
<fragment android:name="com.returnjump.spoilfoil.EditNameFragment"
android:id="#+id/edit_name_fragment_container"
android:layout_weight="1"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:layout="#layout/edit_name_fragment" />
</LinearLayout>
So for the parameter in
fragmentTransaction.add(R.id.edit_name_dialog, fragment, "tag");
this is supposed to reference the id of the fragment, correct?
It still gives me the same error, what am I missing?

There are basically two ways to add a fragment to an activity like the documentation say:
"statically": by declaring the fragment inside the activity's layout file.
"dynamically": adding the fragment programmatically. Like you tried to do.
Here is the documentation: http://developer.android.com/guide/components/fragments.html
If you wish to add it dynamically, here is the documentation part that you want to read:
At any time while your activity is running, you can add fragments to your activity layout. You simply need to specify a ViewGroup in which to place the fragment.
To make fragment transactions in your activity (such as add, remove, or replace a fragment), you must use APIs from FragmentTransaction. You can get an instance of FragmentTransaction from your Activity like this:
FragmentManager fragmentManager = getFragmentManager()
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
You can then add a fragment using the add() method, specifying the fragment to add and the view in which to insert it. For example:
ExampleFragment fragment = new ExampleFragment();
fragmentTransaction.add(R.id.fragment_container, fragment);
fragmentTransaction.commit();
The first argument passed to add() is the ViewGroup in which the fragment should be placed, specified by resource ID, and the second parameter is the fragment to add.
Once you've made your changes with FragmentTransaction, you must call commit() for the changes to take effect.
And about why to use dynamic fragments instead of static fragments, it has been made for interactive UI allowing you to simply handle different fragments into one activity as you please.

Android Fragment is not displayed

I'm quite new to Android dev and I followed the official Android's "Get started".
The fact is, my fragment is not displayed on the main activity ( it worked well few days ago but I changed some lines, I don't remember which ones ). I think it's a very basic problem as I don't use sophisticated fragments : it's basically one fragment inside an activity.
This is my activity :
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container1"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.mysecond.MainActivity"
tools:ignore="MergeRootFrame" />
My fragment :
<RelativeLayout 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:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
</RelativeLayout>
And the java code for this activity (I have some other activities in the app, based on the same pattern "one fragment inside one activity" and they work well...)
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container1, new PlaceholderFragment()).commit();
}
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
return rootView;
}
}
}
Any ideas ?
Thank you :)
[edit]
so this is my new onCreate method :
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getSupportFragmentManager().beginTransaction().replace(
R.id.container1, new PlaceholderFragment()).commit();
}
Still not working for this activity (If I add a button in activity_main.xml I'll be able to see it but the I'm not able to see the TextView in the fragment...)
No errors in logcat and yes the activity is launched (I added some Log.e in onCreate and onCreateView and I cas see them)

In your onCreate methode you don't have to check if the savedInstanceState is null but if the the content of the FrameLayout you use is null
Or you simply always replace the fragment with a new one and ommit any checking.

Instead of add, you can use replace.
You can do it like below shown code:
getSupportFragmentManager().beginTransaction().replace(
R.id.container1, new PlaceholderFragment());

For me this work. Implementa a interface FragmentActions with the init() method and use this
private void showFragment(String fragmentTag){
FragmentTransaction trasaction = getSupportFragmentManager().beginTransaction();
FragmentActions fragment = (FragmentActions) getSupportFragmentManager().findFragmentByTag(fragmentTag);
if(fragment==null ){
if(lastFragmentviewed!=null)
trasaction.hide(lastFragmentviewed);
fragment = (FragmentActions) newInstance(fragmentTag);
trasaction.add(R.id.content_frame,(Fragment) fragment,fragmentTag);
}else{
if(lastFragmentviewed!=null && !lastFragmentviewed.equals(fragment))
trasaction.hide(lastFragmentviewed);
if(getSupportFragmentManager().findFragmentByTag(fragmentTag)!=null){
fragment.init();
trasaction.show((Fragment) fragment);
}else
trasaction.add(R.id.content_frame,(Fragment) fragment,fragmentTag);
}
lastFragmentviewed=(Fragment) fragment;
trasaction.commit();
}

Android crashing at getSupportFragmentManager()

I decided to switch from multiple activities to one activity which switches between fragments however the application now crashes.
Here is the activity I am adding the fragment to
public class MainActivity extends SherlockFragmentActivity{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MyFragment fragment = new MyFragment();
fragment.setArguments(getIntent().getExtras());
getSupportFragmentManager().beginTransaction()
.add(R.id.fragment_container, fragment).commit();
}
Here is the fragment its an observer and has functionality but to save space ill just show the creation
public class MyFragment extends SherlockFragment implements Observer{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.my_fragment, container, false);
}
Heres my_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/my_fragment"
android:layout_width="match_parent"
android:layout_height="match_parent" >
... HAS SOME TEXT VIEWS HERE!
</RelativeLayout>
The crash I get is
02-15 16:17:41.079: E/AndroidRuntime(18668): FATAL EXCEPTION: main
02-15 16:17:41.079: E/AndroidRuntime(18668): java.lang.RuntimeException:
Unable to start activity ComponentInfo{com.example.myapp/com.example.myapp.MainActivity}:
java.lang.IllegalArgumentException:
No view found for id 0x7f040036 for fragment MyFragmentt{41a05910 #0 id=0x7f040036}
Can anyone help me out here? I can't really figure out what is causing this. I know if I comment out getSupportFragmentManager() in main activity (the top code block in this post) it will run just not draw anything in my fragment.
UPDATE
The frame_container which I'm not sure where to place
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent" />

So the way you can use Fragments in your applications are two.
First way is if you declare the Fragment in your xml file like this :
<fragment android:name="com.example.news.ArticleReaderFragment"
android:id="#+id/viewer"
android:layout_weight="2"
android:layout_width="0dp"
android:layout_height="match_parent" />
The second way is if you add / replace your Fragments dynamically to your container which in the most examples is FrameLayout. Here is how you can do that :
In your main FragmentActivity :
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.myFragmentContainer);
}
and in your xml myFragmentContainer.xml is where you place your fragment_container and it looks like :
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
and you are adding and replacing your Fragments like this :
if (findViewById(R.id.fragment_container) != null) {
if (savedInstanceState != null) {
return;
}
// Create an instance of ExampleFragment
HeadlinesFragment firstFragment = new HeadlinesFragment();
// if there are any extras
firstFragment.setArguments(getIntent().getExtras());
// Add the fragment to the 'fragment_container' FrameLayout
getSupportFragmentManager().beginTransaction()
.add(R.id.fragment_container, firstFragment).commit();
}
and for the next Fragment which you want to show just do :
getSupportFragmentManager().beginTransaction()
.replace(R.id.fragment_container, secondFragment).commit();