Change from one fragment to another by means of a button

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Change from one fragment to another by means of a button

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#1 by (2 votes)
#2 by (0 votes)
#3 by (-1 votes)

3

What I try to do is move from one fragment to another when a button is pressed, the code I am using is:

public class DimensionFragment extends Fragment {


    Button Bmeters,
           Bfeet;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        //return inflater.inflate(R.layout.fragment_dimension, container, false);

        View view = inflater.inflate(R.layout.fragment_dimension, container, false);


            Bmeters = (Button) view.findViewById(R.id.buttonmeters);
        Bmeters.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                Intent Bmeters = new Intent( getActivity() ,Meters.class);
                startActivity(Bmeters);
            }
        });




        Bfeet=(Button)view.findViewById(R.id.buttonfeet);







        return view;



    }

But I get the following error when I run

04-26 12: 06: 04.705 3879-3879 / com.example.liantonypozo.calculosmatematicos3 E / AndroidRuntime: FATAL EXCEPTION: main Process: com.example.liantonypozo.calculosmatematicos3, PID: 3879 android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.liantonypozo.calculamatematicos3 / com.example.liantonypozo.calculosmatematicos3.DimensionFragment}; have you declared this activity in your AndroidManifest.xml? at android.app.Instrumentation.checkStartActivityResult (Instrumentation.java:1805) at android.app.Instrumentation.execStartActivity (Instrumentation.java:1523) at android.app.Activity.startActivityForResult (Activity.java:4225) at android.support.v4.app.BaseFragmentActivityJB.startActivityForResult (BaseFragmentActivityJB.java:50) at android.support.v4.app.FragmentActivity.startActivityForResult (FragmentActivity.java:79) at android.support.v4.app.ActivityCompatJB.startActivityForResult (ActivityCompatJB.java:30) at android.support.v4.app.ActivityCompat.startActivityForResult (ActivityCompat.java:146) at android.support.v4.app.FragmentActivity.startActivityFromFragment (FragmentActivity.java:932) at android.support.v4.app.FragmentActivity $ HostCallbacks.onStartActivityFromFragment (FragmentActivity.java:1047) at android.support.v4.app.Fragment.startActivity (Fragment.java:940) at android.support.v4.app.Fragment.startActivity (Fragment.java:929) at com.example.liantonypozo.calculamatematicos3.Fragmen2 $ 2.onClick (Fragmen2.java:52) at android.view.View.performClick (View.java:5637) at android.view.View $ PerformClick.run (View.java:22429) at android.os.Handler.handleCallback (Handler.java:751) at android.os.Handler.dispatchMessage (Handler.java:95) at android.os.Looper.loop (Looper.java:154) at android.app.ActivityThread.main (ActivityThread.java:6119) at java.lang.reflect.Method.invoke (Native Method) at com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run (ZygoteInit.java:886) at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:776)

java android android-studio android-fragment

asked by Liantony Pozo 26.04.2017 в 18:19

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3 answers

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score 2 · Answer 1

It is better to work with separate fragments. for example create your own Layout for the fragment fragment_meters_layout.xml

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/texto_fragment"
    android:layout_gravity="center"
    android:layout_margin="15dp"
    android:padding="15dp"/>

<TextView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:textAlignment="center" />

is just an example.

Then you declare a class that controls it, as you are doing in your other fragment

FragmentMeter.java

public class FragmentMain extends Fragment {

@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View vista = inflater.inflate(R.layout.fragment_meter_layout, container, false);

    return vista;
}
}

the Layout of your activity should be something like this

activity_main.xml

<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
android:layout_height="match_parent">

......

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/contenedor">

</RelativeLayout>

....

If you have your fragments as well, and your activity with a layout that will contain the fragments.

Then in your click event you do the following:

  Bmeters = (Button) view.findViewById(R.id.buttonmeters);
    Bmeters.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            FragmentMeter fr=new FragmentMeter();
            fr.setArguments(bn);
            getActivity().getSupportFragmentManager().beginTransaction()
                    .replace(R.id.contenedor,fr)
                    .addToBackStack(null)
                    .commit();

        }
    });

from a fragment you can access

getSupportFragmentManager () from your activity with getActivity ()

The activity is the one who will change the fragment inside, for that is what you should call the fragment activity

score 0 · Answer 2

The main problem is that you have not declared in your AndroidManifest.xml the Activity calculatosmatematicos3 that would contain the Fragment DimensionFragment:

ActivityNotFoundException: Unable to find explicit activity class {com.example.liantonypozo.calculamatematicos3 / com.example.liantonypozo.calculosmatematicos3.DimensionFragment}

I see that you also make an Intent to open Meters , in this way an Activity is opened but the transaction of a Fragment is not made:

 Intent Bmeters = new Intent( getActivity() ,Meters.class);
 startActivity(Bmeters);

The correct way to change a Fragment is through FragmentTransaction :

 // Crea el nuevo fragmento y la transacción.
 Fragment nuevoFragmento = new BlankFragment();
 FragmentTransaction transaction = getFragmentManager().beginTransaction();
 transaction.replace(R.id.fragment_container, nuevoFragmento);
 transaction.addToBackStack(null);

 // Commit a la transacción
 transaction.commit();

score -1 · Answer 3

with the Bmeters button is trying to change an Activity not to a Fragment. There are 2 types of libraries for Fragment:

android.app.Fragment
android.support.v4.app.Fragment

The first is for API of 11 or more, the second for API 10 or less.
For the app.Fragment library, import these libraries:

import android.app.Fragment;
import android.app.FragmentTransaction;

and thus change fragment ( android.app.Fragment ):

FragmentMeters fragment = new FragmentMeters();
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.frame, fragment, "fragment_meters");
ft.addToBackStack(null);  //opcional, si quieres agregarlo a la pila
ft.commit();

For the support.v4.app.Fragment library, it matters:

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;

This changes the fragment, by clicking on the button, from the DimensionFragment to the FragmentMeters, in case the android.support.v4.app.Fragment library is used:

Bmeters = (Button) view.findViewById(R.id.buttonmeters);
    Bmeters.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
           FragmentMeters fragment = new FragmentMeters();
           FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
           ft.replace(R.id.frame,  fragment, "fragment_meters");
           ft.addToBackStack(null);
           ft.commit();
        }
    });

Inside your layout of the ACTIVITY you must include the Frame Layout:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    ....
    <FrameLayout
        android:id="@+id/frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </FrameLayout>
</RelativeLayout>

Finally, if you add them to the stack, add a background color to the fragments layout so they do not look spliced, or add:

android:background="?android:colorBackground"