How to set AppBarLayout height to 0

Question

My layout file looks like:

<?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/apk/res-auto"
...
android:elevation="0dp"
android:fitsSystemWindows="true">

<android.support.design.widget.AppBarLayout
    android:id="@+id/appbar"
    android:layout_width="match_parent"
    android:layout_height="256dp"
    android:fitsSystemWindows="true"
    android:elevation="0dp"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        android:elevation="0dp"
        app:contentScrim="?attr/colorPrimary"
        app:expandedTitleMarginEnd="50dp"
        app:expandedTitleMarginStart="50dp"
        app:titleEnabled="false"
        app:layout_scrollFlags="scroll|exitUntilCollapsed">

        <android.support.v7.widget.Toolbar
            android:id="@+id/main_toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:elevation="0dp"
            app:layout_collapseMode="pin"
            app:layout_scrollFlags="scroll|enterAlways"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

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

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


<android.support.v7.widget.RecyclerView
    android:id="@+id/recyclerview_worthiness_detail"
    ...
    app:layout_behavior="@string/appbar_scrolling_view_behavior" />

<include layout="@layout/common_view" />

<com.yidoutang.app.widget.DetailAvatarView
    android:id="@+id/iv_header_worthiness_detail"
    android:layout_width="@dimen/header_size_datail"
    android:layout_height="@dimen/header_size_datail"
    android:clickable="true"
    android:elevation="0dp"
    app:backgroundTint="@color/fab_color_primary"
    app:border_color="@color/white"
    app:border_width="1dp"
    app:layout_anchor="@id/appbar"
    app:layout_anchorGravity="bottom|center_horizontal"
    app:layout_behavior="com.yidoutang.app.widget.behavior.AvatarBehavior"
    app:rippleColor="@android:color/darker_gray" />

<include layout="@layout/layout_fab" />

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

I set android: elevation = "0dp" in Toorbar, CoordinatorLayout and AppBarLayout, but when it closes, it still has a mark.

Something like an image

How to remove elavation?

Answer 1

Use app:elevation="0dp"to unmark

Answer 2

Instead

android:elevation="0dp"

to try

app:elevation="0dp"