工具栏的colorPrimary出现在ImageView下方

Question

1. 在CollapsingToolbarLayout容器中使用工具栏和ImageView会导致工具栏的colorPrimary出现在ImageView下方：

https://imgur.com/dQwWRzg

1. 向上滚动页面，工具栏的colorPrimary逐渐消失：

https://imgur.com/rzeOqLf

https://imgur.com/eBpJB14

1. 代码：

activity_main.xml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/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/white"
android:fitsSystemWindows="true">

<android.support.design.widget.AppBarLayout
    android:id="@+id/app_bar_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:fitsSystemWindows="true"
    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"
        app:contentScrim="?attr/colorPrimary"
        app:expandedTitleTextAppearance="@style/TextAppearance.AppCompat.Title"
        app:layout_scrollFlags="scroll|exitUntilCollapsed"
        app:titleEnabled="false">

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="220dp"
            android:fitsSystemWindows="true"
            android:scaleType="centerCrop"
            android:src="@drawable/bg_profile"
            app:layout_collapseMode="parallax" />

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:contentInsetStartWithNavigation="0dp"
            app:layout_collapseMode="pin"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

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

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

<android.support.v4.widget.NestedScrollView
    android:id="@+id/nested_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:clipToPadding="false"
    android:scrollbars="none"
    android:scrollingCache="true"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">

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

<com.modon.circularimageview.CircularImageView
    android:id="@+id/image"
    android:layout_width="100dp"
    android:layout_height="100dp"
    android:src="@drawable/image"
    app:civ_border="true"
    app:civ_border_width="2dp"
    app:layout_anchor="@id/app_bar_layout"
    app:layout_anchorGravity="bottom|center" />

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

Styles.xml

<resources>

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
    <item name="windowActionModeOverlay">true</item>
    <item name="android:actionModeBackground">@color/blue_grey_600</item>
</style>

<style name="Toolbar.Light" parent="@style/AppTheme">
    <item name="colorControlNormal">@color/grey_60</item>
    <item name="android:textColorPrimary">@color/grey_60</item>
</style>

</resources>

colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="colorPrimary">#197333</color>
<color name="colorPrimaryDark">#1565C0</color>
</resources>

MainActivity.java

package com.profile;

import android.os.Bundle;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CollapsingToolbarLayout;
import android.support.v4.view.ViewCompat;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

import com.modon.circularimageview.CircularImageView;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    initToolbar();
    initComponent();
}

private void initToolbar() {
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    toolbar.setNavigationIcon(R.drawable.ic_menu);
    setSupportActionBar(toolbar);
    getSupportActionBar().setTitle("Profile");
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}

private void initComponent() {
    final CircularImageView image = (CircularImageView) findViewById(R.id.image);
    final CollapsingToolbarLayout collapsing_toolbar = (CollapsingToolbarLayout) findViewById(R.id.collapsing_toolbar);
    ((AppBarLayout) findViewById(R.id.app_bar_layout)).addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
        @Override
        public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
            int min_height = ViewCompat.getMinimumHeight(collapsing_toolbar) * 2;
            float scale = (float) (min_height + verticalOffset) / min_height;
            image.setScaleX(scale >= 0 ? scale : 0);
            image.setScaleY(scale >= 0 ? scale : 0);
        }
    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_search_setting, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    if (item.getItemId() == android.R.id.home) {
        finish();
    } else {
        Toast.makeText(getApplicationContext(), item.getTitle(), Toast.LENGTH_SHORT).show();
    }
    return super.onOptionsItemSelected(item);
}

}