RecyclerView and Toolbar, can't scroll bottom item into view

问题

EDIT: See Using the Master/Detail template in ViewPager Fragments (download link) for full code

I have a toolbar and a recyclerView. When the layout is first inflated the last item of the recyclerView is out of the scroll-able region of the screen and is therefore not visible. After rotating the item appears. It is apparent that the toolbar is pushing the recyclerView outside the boundaries of the screen. If I add padding to the bottom of the recyclerView with the height of the toolbar the issue is resolved BUT only for the initial inflation of the layout. After rotation I am left with a gap on the bottom of the screen. I'm using sdk 23.

A possible workaround would be to programmatically remove the padding after the very first inflation of the layout. I assume I could use:

onCreateView(){ if (onSaveInstanceState != null) removePadding();}

However, I'd rather not have to do a dodgy work-around.

My app is basically exactly the same as the Master/Detail-flow template supplied in Android Studio, except that I use fragments and a single Activity. There is no such issue in the template.

Any ideas?

fragment_item_list.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <FrameLayout
        android:id="@+id/frameLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <include layout="@layout/item_list" />
    </FrameLayout>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_margin="@dimen/fab_margin"
        android:src="@android:drawable/ic_dialog_email" />


</android.support.design.widget.CoordinatorLayout>

item_list.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/item_list"
    android:name="com.idragonit.scrolltabs.ItemListFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginLeft="16dp"
    android:layout_marginRight="16dp"
    app:layoutManager="LinearLayoutManager"
    tools:context="com.idragonit.scrolltabs.ItemListActivity"
    tools:listitem="@layout/item_list_content" />

item_list_content.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal">

    <TextView
        android:id="@+id/id"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="@dimen/text_margin"
        android:textAppearance="?attr/textAppearanceListItem" />

    <TextView
        android:id="@+id/content"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="@dimen/text_margin"
        android:textAppearance="?attr/textAppearanceListItem" />
</LinearLayout>

snippet of ItemListFragment.java

Toolbar toolbar = (Toolbar) root.findViewById(R.id.toolbar);
toolbar.setTitle("List");

回答1:

I added:

android:layout_gravity="fill_vertical"
android:layout_marginBottom="?attr/actionBarSize"

to item_list.xml. The issue persists. The first time the layout is inflated it shows the bottom element as expected. After rotating to landscape and back to portrait it leaves a margin the size of the actionBar at the bottom of the screen.

This issue does not happen in the Master/Detail-flow template available in Android Studio and the code for item_list.xml, item_list_twopane.xml and activity_item_list are exactly the same as the code used in item_list.xml, land/item_list.xml and fragment_item_list.xml in my project. Yet, as the attached images show, the preview of the AppBar shows the flexible space in the Android template but not my code.

EDIT: When I click on the reference for "?attr/actionBarSize" in the template it navigates to a different line in android SDK's values.xml, which starts with <declare-styleable name="AppCompatTheme">. The same line of code in my app references a different line starting with<declare-styleable name="Theme">.

Screenshots:

回答2:

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
   xmlns: android="http://schemas.android.com/apk/res/android"
   xmlns:app="http://schemas.android.com/apk/res-auto"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:background="@color/white"
   android:orientation="vertical">

   <android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
         android:id="@+id/toolbar"
         android:layout_width="match_parent"
         android:layout_height="?attr/actionBarSize"
         android:background="?attr/colorPrimary"
         app:popupTheme="@style/AppTheme.PopupOverlay" />

   </android.support.design.widget.AppBarLayout>

   <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/item_list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="5dp"
        android:scrollbars="vertical" />


   </LinearLayout>

   <android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_gravity="bottom|right"
    android:layout_marginBottom="@dimen/activity_vertical_margin"
    android:layout_marginRight="@dimen/activity_horizontal_margin"
    android:src="@drawable/ic_add"
    app:backgroundTint="@color/colorPrimary" />

</android.support.design.widget.CoordinatorLayout>

来源：https://stackoverflow.com/questions/35762827/recyclerview-and-toolbar-cant-scroll-bottom-item-into-view