当用户向上滚动时如何隐藏应用程序栏?

Question

我想在用户向上滚动时隐藏应用程序栏，在用户向下滚动时显示应用程序栏。

我按照这篇文章做了，但是行不通

我正在使用一个可扩展的列表视图。我尝试使用这两个属性:

应用:layout_scrollFlags ="滚动| enterAlways"应用:layout_behavior ="@string/appbar_scrolling_view_behavior"

但它不工作。

这是我的活动XML:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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/relativeLayout5"
android:layout_width="match_parent"
android:layout_height="match_parent">

<include
android:id="@+id/include"
layout="@layout/app_bar_common_light"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />

<ExpandableListView
android:id="@+id/expLvContent"
android:layout_width="0dp"
android:layout_height="0dp"
android:background="@android:color/transparent"
android:childDivider="#00000000"
android:clipToPadding="false"
android:divider="@null"
android:dividerHeight="0dp"
android:groupIndicator="@null"
android:layoutDirection="ltr"
android:orientation="vertical"
android:paddingBottom="10dp"
android:scrollbarSize="5dp"
android:scrollbarStyle="insideOverlay"
android:scrollbarThumbVertical="@color/faq_filter_heading"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
app:layout_constraintBottom_toTopOf="@id/llFooter"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/include" />

<ExpandableListView
android:id="@+id/expLvIndex"
android:layout_width="0dp"
android:layout_height="0dp"
android:background="@android:color/transparent"
android:childDivider="#00000000"
android:clipToPadding="false"
android:divider="@null"
android:dividerHeight="0dp"
android:groupIndicator="@null"
android:layoutDirection="ltr"
android:listSelector="@android:color/transparent"
android:orientation="vertical"
android:paddingBottom="10dp"
android:scrollbarSize="5dp"
android:scrollbarStyle="insideOverlay"
android:scrollbarThumbVertical="@color/faq_filter_heading"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
app:layout_constraintBottom_toTopOf="@id/llFooter"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/include" />

<com.dailyrounds.fontlib.widgets.DRTextView
android:id="@+id/tvExpand"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top|right"
android:background="@drawable/shape_square_round_corner"
android:backgroundTint="@color/expand_all_bg"
android:paddingLeft="10dp"
android:paddingTop="2dp"
android:paddingRight="10dp"
android:paddingBottom="2dp"
android:text="@string/expand_all"
android:textColor="@android:color/black"
app:layout_constraintEnd_toEndOf="@+id/expLvContent"
app:layout_constraintTop_toBottomOf="@+id/include" />

<androidx.appcompat.widget.LinearLayoutCompat
android:id="@+id/llFooter"
android:layout_width="match_parent"
android:layout_height="58dp"
android:background="@color/activity_background"
android:elevation="8dp"
android:gravity="center_horizontal"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent">

<LinearLayout
android:id="@+id/toggleContent"
android:layout_width="wrap_content"
android:layout_height="35dp"
android:layout_gravity="center"
android:background="@drawable/material_group_border"
android:gravity="center"
android:orientation="horizontal"
android:padding="2dp"
android:visibility="visible">

<com.google.android.material.button.MaterialButton
android:id="@+id/btnOutline"
style="@style/Widget.AppCompat.Button.Borderless"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/rounded_corners"
android:backgroundTint="@color/selector_btn_toggle"
android:insetTop="0dp"
android:insetBottom="0dp"
android:text="@string/outlined"
android:textAllCaps="false"
android:textColor="@color/white"
android:textSize="14sp" />

<com.google.android.material.button.MaterialButton
android:id="@+id/btnDetailed"
style="@style/Widget.AppCompat.Button.Borderless"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/rounded_corners"
android:backgroundTint="@color/lightgrey"
android:insetTop="0dp"
android:insetBottom="0dp"
android:text="@string/detailed"
android:textAllCaps="false"
android:textColor="@color/black"
android:textSize="14sp" />
</LinearLayout>
</androidx.appcompat.widget.LinearLayoutCompat>

<ProgressBar
android:id="@+id/pgContent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>
Here is the **app bar XML** file:
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.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/app_bar_main"
android:layout_width="match_parent"
android:layout_height="wrap_content">

<com.google.android.material.appbar.AppBarLayout
android:id="@+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme.AppBarOverlay">

<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
style="@style/ToolBarStyle.Event"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/toolbar_light"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="@style/AppTheme.PopupOverlay"
app:titleTextAppearance="@style/TitleBarTextAppearanceDark">

<com.dailyrounds.fontlib.widgets.DRImageView
android:id="@+id/ivAppBarBack"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="15dp"
android:background="?attr/selectableItemBackground"
android:gravity="center"
android:layoutDirection="ltr"
android:visibility="gone"
tools:visibility="visible"
app:srcCompat="@drawable/ic_arrow_back_charcoal_grey" />

<com.dailyrounds.fontlib.widgets.DRTextView
android:id="@+id/tvAppBarTitle"
style="@style/TitleBarTextAppearanceDark"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="30dp"
android:ellipsize="marquee"
android:gravity="start"
android:layoutDirection="ltr"
tools:visibility="visible"
android:layout_marginBottom="10dp"
android:singleLine="true"
android:visibility="gone"
tools:text="@string/Rx" />
</androidx.appcompat.widget.Toolbar>
</com.google.android.material.appbar.AppBarLayout>

</androidx.coordinatorlayout.widget.CoordinatorLayout>
**EDIT:**
Tried putting activity XML in the coordinator layout, but still, it is not working
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.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/app_bar_main"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.appbar.AppBarLayout
android:id="@+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme.AppBarOverlay">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
style="@style/ToolBarStyle.Event"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/toolbar_light"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="@style/AppTheme.PopupOverlay"
app:titleTextAppearance="@style/TitleBarTextAppearanceDark">
<com.dailyrounds.fontlib.widgets.DRImageView
android:id="@+id/ivAppBarBack"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="15dp"
android:background="?attr/selectableItemBackground"
android:gravity="center"
android:layoutDirection="ltr"
android:visibility="gone"
app:srcCompat="@drawable/ic_arrow_back_charcoal_grey"
tools:visibility="visible" />
<com.dailyrounds.fontlib.widgets.DRTextView
android:id="@+id/tvAppBarTitle"
style="@style/TitleBarTextAppearanceDark"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="30dp"
android:layout_marginBottom="10dp"
android:ellipsize="marquee"
android:gravity="start"
android:layoutDirection="ltr"
android:singleLine="true"
android:visibility="gone"
tools:text="@string/Rx"
tools:visibility="visible" />
</androidx.appcompat.widget.Toolbar>
</com.google.android.material.appbar.AppBarLayout>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="@+id/relativeLayout5"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_anchor="@+id/relativeLayout5"
app:layout_anchorGravity="center">
<ExpandableListView
android:id="@+id/expLvContent"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/transparent"
android:childDivider="#00000000"
android:clipToPadding="false"
android:divider="@null"
android:dividerHeight="0dp"
android:groupIndicator="@null"
android:layoutDirection="ltr"
android:nestedScrollingEnabled="true"
android:orientation="vertical"
android:paddingTop="58dp"
android:paddingBottom="10dp"
android:scrollbarSize="5dp"
android:scrollbarStyle="insideOverlay"
android:scrollbarThumbVertical="@color/faq_filter_heading"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ExpandableListView
android:id="@+id/expLvIndex"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/transparent"
android:childDivider="#00000000"
android:clipToPadding="false"
android:divider="@null"
android:dividerHeight="0dp"
android:groupIndicator="@null"
android:layoutDirection="ltr"
android:listSelector="@android:color/transparent"
android:orientation="vertical"
android:paddingTop="68dp"
android:paddingBottom="10dp"
android:scrollbarSize="5dp"
android:scrollbarStyle="insideOverlay"
android:scrollbarThumbVertical="@color/faq_filter_heading"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:layout_editor_absoluteX="-19dp"
tools:layout_editor_absoluteY="210dp" />
<com.dailyrounds.fontlib.widgets.DRTextView
android:id="@+id/tvExpand"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top|right"
android:background="@drawable/shape_square_round_corner"
android:backgroundTint="@color/expand_all_bg"
android:nestedScrollingEnabled="true"
android:paddingLeft="10dp"
android:paddingTop="2dp"
android:paddingRight="10dp"
android:paddingBottom="2dp"
android:text="@string/expand_all"
android:textColor="@android:color/black"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<androidx.appcompat.widget.LinearLayoutCompat
android:id="@+id/llFooter"
android:layout_width="match_parent"
android:layout_height="58dp"
android:background="@color/activity_background"
android:elevation="8dp"
android:gravity="center_horizontal"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent">
<LinearLayout
android:id="@+id/toggleContent"
android:layout_width="wrap_content"
android:layout_height="35dp"
android:layout_gravity="center"
android:background="@drawable/material_group_border"
android:gravity="center"
android:orientation="horizontal"
android:padding="2dp"
android:visibility="visible">
<com.google.android.material.button.MaterialButton
android:id="@+id/btnOutline"
style="@style/Widget.AppCompat.Button.Borderless"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/rounded_corners"
android:backgroundTint="@color/selector_btn_toggle"
android:insetTop="0dp"
android:insetBottom="0dp"
android:text="@string/outlined"
android:textAllCaps="false"
android:textColor="@color/white"
android:textSize="14sp" />
<com.google.android.material.button.MaterialButton
android:id="@+id/btnDetailed"
style="@style/Widget.AppCompat.Button.Borderless"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/rounded_corners"
android:backgroundTint="@color/lightgrey"
android:insetTop="0dp"
android:insetBottom="0dp"
android:text="@string/detailed"
android:textAllCaps="false"
android:textColor="@color/black"
android:textSize="14sp" />
</LinearLayout>
</androidx.appcompat.widget.LinearLayoutCompat>
<ProgressBar
android:id="@+id/pgContent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>

Answer 1

你的List View和AppBarLayout，需要是同一个CoordinatorLayout的子元素才能工作

Answer 2

listView.setOnScrollListener(new OnScrollListener() {
int mLastFirstVisibleItem = 0;
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {   }           
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {    
if (view.getId() == listView.getId()) {
final int currentFirstVisibleItem = listView.getFirstVisiblePosition();
if (currentFirstVisibleItem > mLastFirstVisibleItem) {
//hide toolbar
} else if (currentFirstVisibleItem < mLastFirstVisibleItem) {
//show toolbar
}
mLastFirstVisibleItem = currentFirstVisibleItem;
}               
}
});

并通过在父布局

中添加android:layoutAnimation="true"来启用布局动画

Answer 3

在应用程序栏XML布局中，您需要将androidx.appcompat.widget.Toolbar替换为com.google.android.material.appbar.CollapsingToolbarLayout，以便在向上滚动时折叠其内容。

同时保持scroll|enterAlways进入CollapsingToolbarLayout