CoordinatorLayout Toolbar invisible on enter until full height

问题

Included in my activity_main.xml's DrawerLayout is a CoordinatorLayout called content_layout.xml. Within this CoordinatorLayout is my AppBarLayout containing a Toolbar, then a LinearLayout for a fragment's content.

When a fragment containing a RecyclerView is scrolled up, the toolbar exits successfully. The problem lies when scrolling down to bring the toolbar back. The toolbar does not appear until the full height of the toolbar has been scrolled and as such leaves an unsightly white box in its place as shown.

content_layout.xml

<android.support.design.widget.CoordinatorLayout
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/container_frame"
    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="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

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

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

    <!-- The main content view for fragments-->
    <LinearLayout
        android:id="@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"/>

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

The toolbar is initialized via MainActivity's onCreate():

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);

I would appreciate any suggestions as to resolving this. Thank you.

回答1:

I was having this same issue and the only thing I found that solved it was by having something else other than the toolbar inside the AppBarLayout. I placed an invisible view in my layout underneath the toolbar. Not the most ideal solution, but it worked.

<android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">      

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

     <View
        android:id="@+id/appbar_bottom"
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="@android:color/transparent"
        android:visibility="invisible"/>

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

来源：https://stackoverflow.com/questions/30895579/coordinatorlayout-toolbar-invisible-on-enter-until-full-height