Scrolling Toolbar not working on Kitkat

Question

This is my main layout:

 <?xml version="1.0" encoding="utf-8"?> <!-- ~ Copyright (c) - Software developed by iClaude. --> <android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:id="@+id/drawer_layout" android:layout_width="match_parent" android:layout_height="match_parent" android:fitsSystemWindows="true"> <android.support.design.widget.CoordinatorLayout android:id="@+id/main_content" android:layout_width="match_parent" android:layout_height="match_parent"> <android.support.design.widget.AppBarLayout android:id="@+id/appbar" android:layout_width="match_parent" android:layout_height="wrap_content" android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" android:elevation="4dp"> <android.support.v7.widget.Toolbar android:id="@+id/toolbar" android:layout_width="match_parent" android:layout_height="?attr/actionBarSize" app:popupTheme="@style/ThemeOverlay.AppCompat.Light" app:layout_scrollFlags="scroll|enterAlways" /> <android.support.design.widget.TabLayout android:id="@+id/sliding_tabs" android:layout_width="match_parent" android:layout_height="wrap_content" style="@style/MioStileTabLayout" app:tabMode="scrollable" /> </android.support.design.widget.AppBarLayout> <!-- The main content view --> <RelativeLayout android:id="@+id/main_rlUpdatingDatabase" android:layout_width="match_parent" android:layout_height="match_parent" android:visibility="visible" > <ProgressBar android:id="@+id/main_pbUpdatingDatabase" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="false" android:layout_centerInParent="true" android:layout_centerVertical="false" android:visibility="visible" /> <TextView android:id="@+id/main_tvUpdatingDatabase" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="false" android:layout_below="@id/main_pbUpdatingDatabase" android:layout_centerHorizontal="false" android:layout_centerInParent="true" android:layout_centerVertical="false" android:text="@string/intro_updatingDatabase" android:textAppearance="?android:attr/textAppearanceMedium" android:visibility="visible" android:textColor="@color/text_secondary" /> </RelativeLayout> <android.support.v4.view.ViewPager android:id="@+id/pager" android:layout_width="match_parent" android:layout_height="wrap_content" android:visibility="invisible" android:layout_marginTop="8dp" app:layout_behavior="@string/appbar_scrolling_view_behavior"/> <android.support.design.widget.FloatingActionButton android:id="@+id/fab" app:fabSize="normal" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/ic_content_new" android:layout_gravity="bottom|end" app:elevation="6dp" app:pressedTranslationZ="6dp" android:layout_marginRight="@dimen/fab_margin_right" android:layout_marginEnd="@dimen/fab_margin_right" android:layout_marginBottom="@dimen/fab_margin_bottom" android:onClick="animateFab" app:layout_behavior="com.flingsoftware.personalbudget.app.utility.RidimensionaFABBehavior"/> <android.support.design.widget.FloatingActionButton android:id="@+id/fabFav" app:fabSize="normal" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/ic_action_important" android:layout_gravity="bottom|end" app:elevation="6dp" app:pressedTranslationZ="6dp" app:backgroundTint="@color/primary" android:layout_marginRight="@dimen/fab_margin_right" android:layout_marginEnd="@dimen/fab_margin_right" android:layout_marginBottom="@dimen/fab_margin_bottom" android:onClick="launchFav" android:alpha="0" /> <android.support.design.widget.FloatingActionButton android:id="@+id/fabMic" app:fabSize="normal" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/ic_action_mic" android:layout_gravity="bottom|end" app:elevation="6dp" app:pressedTranslationZ="6dp" app:backgroundTint="@color/primary" android:layout_marginRight="@dimen/fab_margin_right" android:layout_marginEnd="@dimen/fab_margin_right" android:layout_marginBottom="@dimen/fab_margin_bottom" android:onClick="launchVocRec" android:alpha="0" /> <android.support.design.widget.FloatingActionButton android:id="@+id/fabAgg" app:fabSize="normal" android:visibility="gone" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/ic_content_new" android:layout_gravity="bottom|end" app:elevation="6dp" app:pressedTranslationZ="6dp" app:backgroundTint="@color/primary" android:layout_marginRight="@dimen/fab_margin_right" android:layout_marginEnd="@dimen/fab_margin_right" android:layout_marginBottom="@dimen/fab_margin_bottom" android:onClick="aggiungi" android:alpha="0" /> </android.support.design.widget.CoordinatorLayout> <!-- The navigation drawer --> <android.support.design.widget.NavigationView android:id="@+id/navigation_view" android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_gravity="start"> <RelativeLayout android:layout_width="match_parent" android:layout_height="match_parent"> <include android:id="@+id/navigation_drawer_header_include" layout="@layout/header" /> <ListView android:id="@+id/left_drawer" android:layout_below="@id/navigation_drawer_header_include" android:layout_width="match_parent" android:layout_height="match_parent" android:choiceMode="singleChoice" android:divider="@android:color/transparent" android:dividerHeight="0dp" android:background="@color/nav_drawer_sfondo" /> </RelativeLayout> </android.support.design.widget.NavigationView> </android.support.v4.widget.DrawerLayout> 

With the ViewPager I load a Fragment containing an ExpandableListview (extending ListView). On API 19 Kitkat the Toolbar doesn't scroll in and out of the display when I scroll the list. On API 21 everything works fine. How to solve this issue?

Thank you.

Answer 1

ListView不支持API 21之前的嵌套滚动：在API 21中引入嵌套滚动之前，框架视图实际上不存在API， CoordinatorLayout和AppBarLayout依赖于嵌套滚动。