android - CollapsingToolbarLayout - 展开时隐藏 ImageView，折叠时显示

Question

我想在展开 CollapsingToolbarLayout 时隐藏一个 ImageView( Logo )，并且只在折叠 CollapsingToolbarLayout 时显示 ImageView。 (我知道如何做这个问题的反面)。

正如您从下面的屏幕截图中看到的那样。大桅杆头其实是一个大logo，左边是图片，右边是公司名。在折叠模式下，我只想显示 Logo 的小缩略图。

请问我如何用 XML 或代码完成此操作？代码和截图如下:

<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitCenter"
android:adjustViewBounds="true">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:fitsSystemWindows="true">

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbarlayout_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_scrollFlags="scroll|exitUntilCollapsed"
        app:contentScrim="@color/colorPrimary">

        <ImageView
            android:id="@+id/mast_logo_main"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:scaleType="fitCenter"
            android:adjustViewBounds="true"
            app:layout_collapseMode="parallax"
            app:layout_collapseParallaxMultiplier="0.9"
            android:src="@drawable/uj_logo_rectangle_orange_background" />


        <android.support.v7.widget.Toolbar
            android:layout_width="match_parent"
            android:layout_height="100dp"
            app:contentInsetStart="40dp"
            app:layout_collapseMode="parallax"
            app:layout_scrollFlags="scroll|exitUntilCollapsed|snap" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="80dp"
            android:orientation="horizontal"
            app:layout_collapseMode="pin">

            <ImageView
                android:id="@+id/thumbnail_logo_main"
                android:layout_width="40dp"
                android:layout_height="40dp"
                android:scaleType="fitCenter"
                android:adjustViewBounds="true"
                android:layout_marginTop="50dp"
                android:layout_marginLeft="10dp"
                android:src="@drawable/uj_rgb_logo_01" />

            <LinearLayout
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:orientation="vertical"
                android:layout_weight="4">

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="20dp"
                    android:paddingTop="20dp"
                    android:layout_marginLeft="10dp"
                    android:textSize="20sp"
                    android:textColor="#fff"
                    android:textStyle="bold"

                    android:text="Courses &amp; Programmes"/>

                <android.support.v7.widget.SearchView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"/>

            </LinearLayout>

            <LinearLayout
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1">

                <ImageView
                    android:layout_width="57dp"
                    android:layout_height="40dp"
                    android:layout_marginLeft="5dp"
                    android:layout_marginRight="10dp"
                    android:layout_marginTop="50dp"
                    android:adjustViewBounds="true"
                    android:scaleType="fitCenter"
                    android:src="@drawable/empty_avatar" />

            </LinearLayout>

        </LinearLayout>

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

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

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

Answer 1

按照下面的代码:

AppBarLayout appBarLayout = (AppBarLayout) view.findViewById(R.id.app_bar_layout);
appBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
        @Override
        public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
            if (Math.abs(verticalOffset) == appBarLayout.getTotalScrollRange()) {
                // If collapsed, then do this
                imageViewBigLogo.setVisibility(View.GONE);
                imageViewSmallLogo.setVisibility(View.VISIBLE);
            } else if (verticalOffset == 0) {
                // If expanded, then do this
                imageViewBigLogo.setVisibility(View.VISIBLE);
                imageViewSmallLogo.setVisibility(View.GONE);
            } else {
                // Somewhere in between
                // Do according to your requirement
            }
        }
    }););

感谢this .