嵌套的滚动视图无法识别工具栏

Question

我的项目只有一个由AppBarLayout包围的工具栏，下面还有一个NestedScrollView控件，其中包含一个被LinearLayout包围的CardView布局。现在问题是，嵌套滚动会重叠在工具栏上，就像我在图片中展示的那样： 而且在运行时，它会使应用程序看起来好像没有工具栏，就像这样： 以下是我的代码：

<?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/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
   <android.support.design.widget.AppBarLayout
      android:id="@+id/appbarLayout"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:fitsSystemWindows="true"
      >



<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/colorPrimary"
    android:elevation="7dp"
    app:theme="@style/ThemeOverlay.AppCompat"
    android:popupTheme="@style/ThemeOverlay.AppCompat.Light"

    android:titleTextColor="@color/colorPrimary"
    app:layout_scrollFlags="scroll|enterAlways"
    ></android.support.v7.widget.Toolbar>
    </android.support.design.widget.AppBarLayout>

    <android.support.v4.widget.NestedScrollView

        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:nestedScrollingEnabled="true"

        >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical"
            android:paddingTop="10dp"

            >
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
        </LinearLayout>

    </android.support.v4.widget.NestedScrollView>

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

scroll_view_item 代码如下：

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
    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="wrap_content"
    android:layout_margin="16dp"
    android:elevation="5dp"
    app:cardCornerRadius="5dp">
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="15dp"
    android:orientation="vertical"

    >
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Dummy Header"
        android:textColor="@android:color/holo_red_light"
        android:textSize="20sp"
        android:textStyle="bold"
        />
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="5dp"
        android:text="@string/app_text"
        />

</LinearLayout>
</android.support.v7.widget.CardView>

- Hussein Ojaghi

---

只是一条注释：在工具栏上，app:theme已经被弃用。请使用android:theme，它可以在较低版本的Android上运行。 - pdegand59

Answer 1

只需像这样将您的代码包装在LinearLayout中：

<?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/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        >
   <android.support.design.widget.AppBarLayout
      android:id="@+id/appbarLayout"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:fitsSystemWindows="true"
      >



<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/colorPrimary"
    android:elevation="7dp"
    app:theme="@style/ThemeOverlay.AppCompat"
    android:popupTheme="@style/ThemeOverlay.AppCompat.Light"

    android:titleTextColor="@color/colorPrimary"
    app:layout_scrollFlags="scroll|enterAlways"
    ></android.support.v7.widget.Toolbar>
    </android.support.design.widget.AppBarLayout>

    <android.support.v4.widget.NestedScrollView

        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:nestedScrollingEnabled="true"

        >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical"
            android:paddingTop="10dp"

            >
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
            <include layout="@layout/scroll_view_item" />
        </LinearLayout>

    </android.support.v4.widget.NestedScrollView>
    </LinearLayout>
</android.support.design.widget.CoordinatorLayout>

- AndroidDev

---

这看起来像是一个黑客攻击，但正确的答案已经由@pdengand59发布了。 - akshay bhange

Answer 2

您忘记在ScrollView上指定行为。

请将以下行添加到您的NestedScrollView：

app:layout_behavior="@string/appbar_scrolling_view_behavior"

- pdegand59

Answer 3

在您的 NestedScrollView 下添加以下行：

app:layout_behavior="@string/appbar_scrolling_view_behavior"

- Sabeeh