CollapsingToolbarLayout 不显示 RecyclerView

CollapsingToolbarLayout doesn't show the RecyclerView

我正在尝试使用折叠工具栏布局实现 Coordinator Layout,并在 运行 应用工具栏折叠正常但回收器视图未显示时将回收器视图放入 nestedScrollView

这是我的 xml 代码:

<android.support.design.widget.CoordinatorLayout 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="match_parent">

    <android.support.v4.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="fill_vertical"
        android:background="#444"
        android:fillViewport="true"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Hello Wolrd" />

            <android.support.v7.widget.RecyclerView
                android:id="@+id/rec"
                android:layout_width="match_parent"
                android:background="#00FFCC"
                android:layout_height="match_parent" />

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

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"

        android:layout_height="wrap_content">

        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/collapsing_toolbar"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimary"
            app:expandedTitleMarginEnd="64dp"
            app:expandedTitleMarginStart="48dp"
            app:layout_scrollFlags="scroll|exitUntilCollapsed">

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:layout_scrollFlags="scroll|enterAlways"/>

            <ImageView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:minHeight="100dp"
                android:scaleType="centerCrop"
                android:src="@drawable/pic"
                app:layout_collapseMode="parallax"
                app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed" />

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


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

</android.support.design.widget.CoordinatorLayout>
  1. 在我看来你根本不需要 NestedScrollView
  2. 尝试将 LinearLayout 的身高(parent 的 RecyclerView)设置为 match_parent 而不是 wrap_content