fragments in viewpager, no view found error

Question

I have an activity holding a fragment, in this fragment there is a button , when it is clicked, a dialog is popped out.

In this dialog, there is a Viewpager, which

Answer 1

so far, we can't figure out why there is an error, but I have a way to work around this, using this tip:

Tip: If you want a custom dialog, you can instead display an Activity as a dialog instead of using the Dialog APIs. Simply create an activity and set its theme to Theme.Holo.Dialog in the manifest element:

Based on this tip, I don't make PagerDialog extend Dialog but from Fragment. And then put this Fragment inside an Activity , set the theme of this activity as above in AndroidManifest.xml.

The updated code for the PagerDialog is as followed.

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class PagerDialog extends Fragment {

ViewPager mViewPager;
FragmentStatePagerAdapter mAdapter;

@Override
public View onCreateView(LayoutInflater inflater,
        @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v = inflater.inflate(R.id.dialog, container, false);
    mViewPager = (ViewPager) v.findViewById(R.id.pager);
    mAdapter = new MyAdapter(getFragmentManager());
    mViewPager.setAdapter(mAdapter);
    return v;
}

private class MyAdapter extends FragmentStatePagerAdapter {

    public MyAdapter(FragmentManager fm) {
        super(fm);

    }

    @Override
    public Fragment getItem(int index) {
        return new DummyFragment();
    }

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

}

private class DummyFragment extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater,
            @Nullable ViewGroup container,
            @Nullable Bundle savedInstanceState) {

        View v = inflater.inflate(R.layout.fragment_dummy_layout,
                container, false);
        return v;
    }
}
}

If you have any better solutions or you can find out why the original code in my question does not work, please teach me. I am a newbie in Android programing and I am happy to learn from you all.

Cheers.