Android Go back to the same snippet after clicking on the first goto snippet in the pager view

Question

I developed one application in that I used a pager view using a snippet. In this, I go from one page to another using the class.in fragment in the second fragment class. I have one button on what I am writing the encoding to go directly to the first fragment through fragment.replace, but after replacing the first fragment I do not scroll the pager page one by one, because when I click the "Back" button, I go to the first fragment, but I cannot return to this class. So I have no idea to move the move / scroll page again to go to the second snippet. please help me quickly, thanks in advance.

My first follewing class:

enter code here
         public class ViewPagerMainActivity extends FragmentActivity implements
    OnClickListener, OnPageChangeListener {

   // all variable declare here
@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);



    getWindow().setFlags(
            WindowManager.LayoutParams.FLAG_FULLSCREEN
                    | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD,
            WindowManager.LayoutParams.FLAG_FULLSCREEN
                    | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
                    );

    setTheme(android.R.style.Theme_Light_NoTitleBar);


    setContentView(R.layout.view_pager_main);
    // other code here

}

private class MyPagerAdapter extends FragmentPagerAdapter {

    public MyPagerAdapter(
            android.support.v4.app.FragmentManager fragmentManager) {
        super(fragmentManager);
    }

    @Override
    public Fragment getItem(int pos) {
        switch (pos) {

        case 0:
            return FirstFragment.newInstance("");

        case 1:
            return SecondFragment.newInstance("");

        default:
            return SecondFragment.newInstance("Default");
        }
    }

    @Override
    public int getCount() {
        return 2; // return no of fragment created by us
    }
}

@Override
public void onClick(View v) {

}

@Override
public void onPageScrollStateChanged(int arg0) {
    // TODO Auto-generated method stub

}

@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
    // TODO Auto-generated method stub

}

@Override
public void onPageSelected(int arg0) {
    // TODO Auto-generated method stub

}
@Override
public void onBackPressed() {
    // TODO Auto-generated method stub
}

}

enter code here  SECOND FILE
           public class FirstFragment extends Fragment implements OnTouchListener {

      // all variable decalre here
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    getActivity().setTheme(android.R.style.Theme_Light_NoTitleBar);
    v = inflater.inflate(R.layout.sliding_lock_pager, container, false);

    // other code here
    return v;
}

public static FirstFragment newInstance(String text) {

    FirstFragment f = new FirstFragment();
    Bundle b = new Bundle();
    b.putString("msg", text);
    f.setArguments(b);

    return f;
}

@Override
public boolean onTouch(View v, MotionEvent event) {
    return false;
}

} third file enter the code here Public class SecondFragment extends Fragment implements OnClickListener {

// all varible decalare here
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    getActivity().setTheme(android.R.style.Theme_Light_NoTitleBar);
    View v = inflater.inflate(R.layout.password, container, false);

    // other code here
    // this method move to main pager 
    txtBack.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            final android.support.v4.app.FragmentTransaction ft = getFragmentManager()
                    .beginTransaction();

                ft.replace(R.id.layputMainPager, new FirstFragment(),
                        "NewFragmentTag");
                ft.addToBackStack(null);
                ft.commit();
        }
    });

    return v;
}

public static SecondFragment newInstance(String text) {

    SecondFragment f = new SecondFragment();
    Bundle b = new Bundle();
    b.putString("msg", text);
    f.setArguments(b);
    return f;
}

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub

}

}

   See in secondFragment class when i back through back button then i want to scroll again to that page i not do that. i move again to that page though page scroll. and in ft.replace(R.id.layputMainPager, new FirstFragment()) R.id.layputMainPager is  `class ViewPagerMainActivity` class xml files a

main layout identifier.

Answer 1

I experienced the same problem a few days ago, I think you are mixing two different implementations:

• If you use fragments with ViewPager. You can use the setCurrentItem () ViewPager method to go to the next or previous fragment.

• If you use fragments only, then you can use the FragmentTransaction class methods, such as replace (), add (), etc. to move between fragments.

Hope this clears everything up. Please share the code if something else is unclear.

onBackPressed() :

@Override
public void onBackPressed() {
    // you can also check for current viewpager item by 
    // mViewpager.getCurrentItem()  
     mViewPager.setCurrentItem(precFragment, true);

}

Button , - :

Button back =  (Button) rootView.findViewById(R.id.back_button);
back.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            ((YourActivity)getActivity()).mViewPager.setCurrentItem(prevFragment);

        }
    });

:

  public class MainActivity extends Activity {

/**
 * The {@link android.support.v4.view.PagerAdapter} that will provide
 * fragments for each of the sections. We use a {@link FragmentPagerAdapter}
 * derivative, which will keep every loaded fragment in memory. If this
 * becomes too memory intensive, it may be best to switch to a
 * {@link android.support.v13.app.FragmentStatePagerAdapter}.
 */
SectionsPagerAdapter mSectionsPagerAdapter;

/**
 * The {@link ViewPager} that will host the section contents.
 */
ViewPager mViewPager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Create the adapter that will return a fragment for each of the three
    // primary sections of the activity.
    mSectionsPagerAdapter = new SectionsPagerAdapter(getFragmentManager());

    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mSectionsPagerAdapter);

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public void onBackPressed() {

     mViewPager.setCurrentItem(0, true);

}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
 * one of the sections/tabs/pages.
 */
public class SectionsPagerAdapter extends FragmentPagerAdapter {

    public SectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        switch (position) {
        case 0:
            return new FirstFragment();
        case 1:
            return new SecondFragment();
        default:
            break;
        }
        return null;
    }

    @Override
    public int getCount() {
        return 2;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        Locale l = Locale.getDefault();
        switch (position) {
        case 0:
            return getString(R.string.title_section1).toUpperCase(l);
        case 1:
            return getString(R.string.title_section2).toUpperCase(l);
        }
        return null;
    }
}

 }

FirstFragment

  public class FirstFragment extends Fragment {
/**
 * The fragment argument representing the section number for this
 * fragment.
 */
private static final String ARG_SECTION_NUMBER = "section_number";

/**
 * Returns a new instance of this fragment for the given section number.
 */
public static FirstFragment newInstance(int sectionNumber) {
    FirstFragment fragment = new FirstFragment();
    Bundle args = new Bundle();
    args.putInt(ARG_SECTION_NUMBER, sectionNumber);
    fragment.setArguments(args);
    return fragment;
}

public FirstFragment() {
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_first, container,
            false);
    Button next =  (Button) rootView.findViewById(R.id.button1);
    next.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            ((MainActivity)getActivity()).mViewPager.setCurrentItem(1);

        }
    });
    return rootView;
}
}

SecondFragment

 public class SecondFragment extends Fragment {
/**
 * The fragment argument representing the section number for this
 * fragment.
 */
private static final String ARG_SECTION_NUMBER = "section_number";

/**
 * Returns a new instance of this fragment for the given section number.
 */
public static SecondFragment newInstance(int sectionNumber) {
    SecondFragment fragment = new SecondFragment();
    Bundle args = new Bundle();
    args.putInt(ARG_SECTION_NUMBER, sectionNumber);
    fragment.setArguments(args);
    return fragment;
}

public SecondFragment() {
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.second_fragment, container,
            false);

    Button back =  (Button) rootView.findViewById(R.id.button1);
    back.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            ((MainActivity)getActivity()).mViewPager.setCurrentItem(0);

        }
    });
    return rootView;
}
 }

. onBackPressed() back.setOnClickListener() SecondFragment. ,

Answer 2

.

    @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,  Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_first, container, false);
    Button next = (Button) rootView.findViewById(R.id.button1);
    next.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            ((MainActivity) getActivity()).mViewPager.setCurrentItem(1);

        }
    });
    return rootView;
}

:

public class FirstFragment extends Fragment {

private static final String ARG_SECTION_NUMBER = "section_number";

private OnSetCurrentItemListener mListener;
private int mSection;

public interface OnSetCurrentItemListener {
    void onGotoItem(int position);
}


public static FirstFragment newInstance(int sectionNumber) {
    FirstFragment fragment = new FirstFragment();
    Bundle args = new Bundle();

    args.putInt(ARG_SECTION_NUMBER, sectionNumber);
    fragment.setArguments(args);
    return fragment;
}


// This method pass a listener to the activity through Fragment LifeCycle creation.
// No needs to cast you Activity cause the method bring it; 
@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    try {
        mListener = (OnSetCurrentItemListener) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString() + " needs to implement OnSetCurrentItemListener");
    }
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    Bundle extras = getArguments();
    mSection = extras.getInt(ARG_SECTION_NUMBER);
}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,  Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_first, container, false);
    Button next = (Button) rootView.findViewById(R.id.button1);
    next.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            int target = mSection + 1;
            target = (target < 0) ? 0 : target; //checks bounds
            //to go next
            mListener.onGotoItem(mSection + 1);
            //to prev
            //mListener.onGotoItem(mSection - 1);
        }
    });
    return rootView;
}
}

:

public class ViewPagerMainActivity extends FragmentActivity implements OnSetCurrentItemListener {

...

@Override
public void onGotoItem(int position) {
    mViewPager.setCurrentItem(position);

}