问题
In Android, how can I get the CollapsingToolbar to stop collapsing if the NestedScrollView runs out of content to scroll? This functionality currently exists in the Contacts app on Android 5.1.1. However, in my code when the NestedScrollView stops scrolling the toolbar continues to collapse leaving gap between the two.
<?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: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="256dp"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_scrollFlags="scroll|exitUntilCollapsed"
app:contentScrim="?attr/colorPrimary"
app:expandedTitleMarginStart="@dimen/content_padding_normal"
app:expandedTitleMarginEnd="64dp">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:titleTextAppearance="@style/ActionBar.TitleText"
app:layout_collapseMode="pin" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
android:scrollbars="none">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:paddingBottom="@dimen/keyline_2">
<android.support.v7.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="@dimen/element_spacing_normal">
<include
layout="@layout/ViewLoadingIndeterminate" />
<LinearLayout
android:id="@+id/progress_status_container"
style="@style/ConnectionFieldContainer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:orientation="vertical"
android:visibility="visible">
<Spinner
android:id="@+id/progress_status"
android:layout_width="match_parent"
style="@style/Text.ConnectionField" />
<TextView
style="@style/Text.ConnectionLabel"
android:text="@string/mobile.customer.connect.progress.status" />
</LinearLayout>
</android.support.v7.widget.CardView>
<android.support.v7.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="@dimen/element_spacing_normal">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:id="@+id/email1_container"
style="@style/ConnectionFieldContainer"
android:orientation="horizontal"
tools:visibility="visible">
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/email1"
style="@style/Text.ConnectionField"
tools:text="bgnosis@gmail.com" />
<TextView
style="@style/Text.ConnectionLabel"
android:text="@string/mobile.customer.connect.email1" />
</LinearLayout>
<ImageButton
android:id="@+id/action_email1"
style="@style/Button.ConnectionAction"
android:src="@drawable/ic_email_black_24dp" />
</LinearLayout>
<LinearLayout
android:id="@+id/email2_container"
style="@style/ConnectionFieldContainer"
android:orientation="horizontal"
tools:visibility="visible">
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/email2"
style="@style/Text.ConnectionField"
tools:text="alternate@email.com" />
<TextView
style="@style/Text.ConnectionLabel"
android:text="@string/mobile.customer.connect.email2" />
</LinearLayout>
<ImageButton
android:id="@+id/action_email2"
style="@style/Button.ConnectionAction"
android:src="@drawable/ic_email_black_24dp" />
</LinearLayout>
<LinearLayout
android:id="@+id/phone_day_container"
style="@style/ConnectionFieldContainer"
android:orientation="horizontal"
tools:visibility="visible">
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/phone_day"
style="@style/Text.ConnectionField"
tools:text="801-555-1234" />
<TextView
style="@style/Text.ConnectionLabel"
android:text="@string/mobile.customer.connect.phone.day" />
</LinearLayout>
<ImageButton
android:id="@+id/action_call_phone_day"
style="@style/Button.ConnectionAction"
android:src="@drawable/ic_call_black_24dp" />
<ImageButton
android:id="@+id/action_text_phone_day"
style="@style/Button.ConnectionAction"
android:src="@drawable/ic_textsms_black_24dp" />
</LinearLayout>
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
<android.support.design.widget.FloatingActionButton
android:id="@+id/create_reminder"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_anchor="@id/collapsing_toolbar"
app:layout_anchorGravity="bottom|right|end"
app:borderWidth="0dp"
app:elevation="@dimen/shadow_size"
android:layout_marginBottom="@dimen/keyline_1"
android:layout_marginRight="@dimen/keyline_1"
android:src="@drawable/ic_alarm_add_white_24dp"
app:backgroundTint="?attr/colorAccent" />
</android.support.design.widget.CoordinatorLayout>
来源：https://stackoverflow.com/questions/31117510/stop-collapsingtoolbar-from-collapsing-after-nestedscrollview-runs-out-of-conten