用户向上滚动时如何隐藏应用栏？答案

【问题标题】：How to hide app bar when user scrolls up?用户向上滚动时如何隐藏应用栏？
【发布时间】：2021-02-27 08:21:22
【问题描述】：

我想在用户向上滚动时隐藏应用栏并在用户向下滚动时显示应用栏。

我关注了这个article，但它不起作用

我正在使用可扩展列表视图。我尝试使用这两个属性：

app:layout_scrollFlags="scroll|enterAlways" app:layout_behavior="@string/appbar_scrolling_view_behavior"

但它不起作用。

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>

【问题讨论】：

你可以把它们放在 NestedScrollView 或 ScrollView 中。这意味着你的父母应该是 ScrollView。

标签： android xml android-appbarlayout

【解决方案1】：

您的列表视图和 AppBarLayout 需要是同一个 CoordinatorLayout 的子级才能正常工作。

【讨论】：

我已经编辑了代码，请看一下。它仍然无法正常工作。

【解决方案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

【讨论】：

【解决方案3】：

在应用栏 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。

还将scroll|enterAlways 保留在CollapsingToolbarLayout 中

【讨论】：