这次实现标题栏随着上滑下滑显示隐藏

实现这个效果需要，Support Design库中的CoordinatorLayout和AppBarLayout进行配合才行。

dependencies {
    ...
    implementation 'com.android.support:design:27.1.1' //必须添加
    implementation 'com.android.support:cardview-v7:27.1.1'
    implementation 'com.github.CymChad:BaseRecyclerViewAdapterHelper:2.9.22'
   
}

xml布局代码

<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <android.support.v7.widget.Toolbar
            android:layout_width="match_parent"
            app:title="我是标题"
            app:titleTextColor="#fff"
            android:id="@+id/toolbar"
            app:layout_scrollFlags="scroll|enterAlways" //这个属性实现随着页面滚动标题栏（toolbar）显示隐藏
            android:background="@color/colorPrimary"
            app:navigationIcon="@drawable/ic_back"
            android:layout_height="50dp">

        </android.support.v7.widget.Toolbar>
    </android.support.design.widget.AppBarLayout>
    <android.support.v7.widget.RecyclerView
        android:layout_width="match_parent"
        android:id="@+id/recycle"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"//这个属性只有在布局是CoordinatorLayout 时才有，是让让控件在AppBarLayout之下的
        android:layout_height="match_parent">

    </android.support.v7.widget.RecyclerView>

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

Activity代码

public class MainActivity extends AppCompatActivity {
    Toolbar toolbar;
    RecyclerView recyclerView;
    private BaseQuickAdapter<String, BaseViewHolder> baseQuickAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        toolbar=findViewById(R.id.toolbar);
        recyclerView=findViewById(R.id.recycle);
        setSupportActionBar(toolbar);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        final ArrayList<String> strings = new ArrayList<>();
        for(int x=0;x<10;x++){
            strings.add("我是条目"+x);
        }
        baseQuickAdapter = new BaseQuickAdapter<String, BaseViewHolder>(R.layout.item, strings) {
            @Override
            protected void convert(BaseViewHolder helper, String item) {
                helper.setText(R.id.tv_title, item);
            }
        };
        baseQuickAdapter.openLoadAnimation(BaseQuickAdapter.SLIDEIN_LEFT);
//        baseQuickAdapter.isFirstOnly(false);
        baseQuickAdapter.setOnItemChildClickListener(new BaseQuickAdapter.OnItemChildClickListener() {
            @Override
            public void onItemChildClick(BaseQuickAdapter adapter, View view, int position) {

            }
        });
        recyclerView.setAdapter(baseQuickAdapter);
    }
}

还需要在主题中将标题去掉

 <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <item name="windowActionBar">false</item> //去掉ActionBar
        <item name="windowNoTitle">true</item> //去掉标题
    </style>

扩展一：将Toolbar换成ImageView和TabLayout实现图片显示隐藏

xml布局代码

<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <ImageView
            android:layout_width="match_parent"
            android:src="@mipmap/bg"
            android:scaleType="fitXY"
            app:layout_scrollFlags="scroll|exitUntilCollapsed" //将layout_scrollFlags属性加在ImageView上
            android:layout_height="200dp" />
        <android.support.design.widget.TabLayout
            android:layout_width="match_parent"
            android:background="#fff"
            app:tabMode="fixed"
            app:tabGravity="fill"
            android:layout_height="wrap_content">
            <android.support.design.widget.TabItem
                android:layout_width="wrap_content"
                android:text="分组一"
                android:layout_height="wrap_content" />
            <android.support.design.widget.TabItem
                android:layout_width="wrap_content"
                android:text="分组二"
                android:layout_height="wrap_content" />
            <android.support.design.widget.TabItem
                android:layout_width="wrap_content"
                android:text="分组三"
                android:layout_height="wrap_content" />
        </android.support.design.widget.TabLayout>
    </android.support.design.widget.AppBarLayout>
    <android.support.v7.widget.RecyclerView
        android:layout_width="match_parent"
        android:id="@+id/recycle"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        android:layout_height="match_parent">

    </android.support.v7.widget.RecyclerView>

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