Navigation Drawer and Page Viewer in android

Question

EDIT :

After the recommendation of using TabStrip instead, I have been searching for it and I decided to used it instead of I was trying to do. So the problem is still the same but different code: In my navigation drawer I have a switch, which gives a Fragment fragment a Fragment value, and when I extend my TodayFragment with FragmentActivity I can´t make the last assignment because it throws a type mismatch error.

So here is part of the code (TodayFragment is now TodayFrag because I'm trying things without erasing classes):

Fragment fragment = null;
switch (position) {
case 0:
    fragment = new HomeFragment();
    break;
case 1:
    fragment = new TimetablesFragment();
    break;
case 2:
    fragment = new SubjectsFragment();
    break;
case 3:
    fragment = new TodayFrag();
    break;
case 4:
    fragment = new Others2Fragment();
    break;

default:
    break;
}

And now I have my PagerTabStrib from http://blog.pboos.ch/android-pagertabstrip-viewpager/ class:

public class TodayFrag extends FragmentActivity {}

ORIGINAL QUESTION:

I have my navigation drawer done, and in a certain point, i switch a position variable to determine which fragment I need to set in the view:

Fragment fragment = null;
switch (position) {
case 0:
    fragment = new HomeFragment();
    break;
case 1:
    fragment = new OneFragment();
    break;
case 2:
    fragment = new TwoFragment();
    break;
case 3:
    fragment = new TodayFragment();
    break;
case 4:
    fragment = new Others2Fragment();
    break;

default:
    break;
}

All fragments are classes that just extends Fragment except for TodayFragment(). TodayFragment() extends Fragment and implements ActionBar.TabListener because I'm trying to achieve a tab swipeable view in one of the fragments of the Navigation drawer:

public class TodayFragment extends Fragment implements ActionBar.TabListener {}

The problem comes in the first part of the code, it says "Type mismatch: cannot convert from TodayFragment to Fragment"

I don't know too much Java, and I'm stuck.

I hope someone could help

Thanks in advance

can you post the piece of code where the problem occurs ?! – S.Thiongane May 04 '14 at 18:58 — S.Thiongane, May 04 '14 at 18:58
It is posted, it is the first big part of code – user1903 May 04 '14 at 19:19 — user1903, May 04 '14 at 19:19

myanimal · Answer 1 · 2014-05-04T21:28:46.077

0

A better approach for tabs in a Fragment is to use a combination of ViewPager and PagerTabStrip as per the example at http://blog.pboos.ch/android-pagertabstrip-viewpager/

Keep in mind that ViewPager is from the support library, so you'll also have to use Fragments from the support library.

Original (incorrect) answer:

You need to cast your TodayFragment to a Fragment:

fragment = (Fragment) new TodayFragment();

edited May 04 '14 at 21:28

answered May 04 '14 at 18:55

myanimal

3,580
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26

`TodayFragment` already extends `Fragment`, no need to cast it again ! – S.Thiongane May 04 '14 at 18:59
1

You're right. Not sure what I was thinking. He may be importing different ```Fragment``` classes in his activity and ```TodayFragment``` (native fragment vs support fragment). Just a guess though. – myanimal May 04 '14 at 19:04
Not that, I have tried that just in case, but it doesn't fix anything. I think the error can come because of the implements part, but not sure how to make it work – user1903 May 04 '14 at 19:20
I usually use a ```ViewPager``` with a ```PagerTabStrip``` when I want tabs in a Fragment. Not familiar with the ```ActionBar.TabListener```. – myanimal May 04 '14 at 19:33
could you give me more information about it? Maybe I can change it – user1903 May 04 '14 at 19:36
That example is really good, I think that even better than what I was trying to do. But I think that extending FragmentActivity will make that the app keeps throwing the same error :S – user1903 May 04 '14 at 20:11
@myanimal yes I think it's due to that. So please update your answer ! The downvotes will disapear automatically :) – S.Thiongane May 04 '14 at 21:00

score 0 · Accepted Answer · answered May 04 '14 at 21:14

As said Myanimal in his answer's comments, I think you have imported different classes of Fragment.

this android.app.Fragment
and this android.support.v4.app.Fragment

The ActionBar.TabListener you implemented or the TabStrip you are using are not the causes of the issue.

When an A class extends/implements a B class, the A class (the subclass) has the "same" properties as B (the base class):

public class A extends B ==> B b = new A(); is possible.

So try to remove all your imports and do CtrlShiftO to organize the imports. Then chose the same class of Fragments. The issue may disappear.

So, I did everything you said but I've changed the ActionBar.TabListener because I want to use TabStrip but this one uses FragmentActivity and I can't manage to make it work; I willedit and update the question so it can be understood easily. — user1903, May 05 '14 at 09:26

Navigation Drawer and Page Viewer in android

2 Answers2