Fragment visible every second view in Viewpager

Question

I'm currently trying to include 2 Fragments inside a Viewpager Fragment. All works fine, but if I scroll 2 Fragments further and return to the one with the two fragments only the upper one is visible(Fragment B is invisible). If i do this again both are visible again. The onResume-Event is called in Fragment B but it is not shown. Layout XML:

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >
        <FrameLayout
            android:id="@+id/a_fragment"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:background="@color/android_color_blue_dark"/>
        <FrameLayout
            android:id="@+id/b_fragment"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:background="@color/android_color_green_dark" />
    </LinearLayout>

Parent Fragment Code in onCreateView()

    if (v.findViewById(R.id.a_fragment) != null) {
        FragmentManager mgr = getChildFragmentManager();
        Fragment f = mgr.findFragmentByTag(TAG_A_FRAGMENT);
        if (f == null) {
            f = new FragmentA();
        }
        FragmentTransaction transaction = mgr.beginTransaction();
        transaction.replace(R.id.a_fragment, f, TAG_S_FRAGMENT);
        transaction.commit();
    }
    if (v.findViewById(R.id.b_fragment) != null) {

        FragmentManager mgr = getChildFragmentManager();
        Fragment f = mgr.findFragmentByTag(TAG_B_FRAGMENT);
        if (f == null) {
            f = new FragmentBLogin();
        }
        FragmentTransaction transaction = mgr.beginTransaction();
        transaction.replace(R.id.b_fragment, f,
                TAG_B_FRAGMENT);
        transaction.commit();
    }

I do add those Fragments dynamically even if they are static to prevent this Error.

I just searched threw the code and nothing found in terms of "setVisibility" or something. Fun fact. It is visible every second time you scroll over it. — LeDon

LeDon LeDon · Accepted Answer · 2013-07-05T14:59:13

I fixed as follows. Got no explanation right now why it works this way and not the other way too.

if (v.findViewById(R.id.a_fragment) != null) {
    FragmentManager mgr = getChildFragmentManager();
    Fragment f = mgr.findFragmentByTag(TAG_A_FRAGMENT);
    if (f == null) {
        f = new FragmentA();
    FragmentTransaction transaction = mgr.beginTransaction();
    transaction.replace(R.id.a_fragment, f, TAG_S_FRAGMENT);
    transaction.commit();
    }
}
if (v.findViewById(R.id.b_fragment) != null) {

    FragmentManager mgr = getChildFragmentManager();
    Fragment f = mgr.findFragmentByTag(TAG_B_FRAGMENT);
    if (f == null) {
        f = new FragmentBLogin();
    FragmentTransaction transaction = mgr.beginTransaction();
    transaction.replace(R.id.b_fragment, f,
            TAG_B_FRAGMENT);
    transaction.commit();
    }
}

Fragment visible every second view in Viewpager

1 Answers