高级UI-符合MD的常用控件

在Google提供的控件中，在support-design及v4，v7包中，存在着很多符合MD标准的控件，这里罗列出一些常用的控件

TextInputLayout

这个控件在作为输入框的时候是极其方便及好用的，结合EditText使用

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical">

    <android.support.design.widget.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:counterEnabled="true"
        app:counterMaxLength="10">

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="请输入用户名" />
    </android.support.design.widget.TextInputLayout>

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入密码" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="登录" />

</LinearLayout>

效果

SearchView

搜索功能，位于ActionBar的位置
首先需要编写menu布局

<?xml version="1.0" encoding="utf-8"?>
<menu 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"
    tools:context=".MainActivity">

    <item android:id="@+id/menu_search"
        android:orderInCategory="100"
        app:showAsAction="always"
        app:actionViewClass="android.support.v7.widget.SearchView"
        android:title="search"/>
    <item android:id="@+id/menu_share"
        android:orderInCategory="100"
        app:showAsAction="ifRoom"
        android:icon="@android:drawable/ic_menu_share"
        android:title="share" />
</menu>

然后复写onCreateOptionsMenu()方法

public class MainActivity extends AppCompatActivity {

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

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        MenuItem menuItem = menu.findItem(R.id.menu_search);
        final SearchView searchView = (SearchView) MenuItemCompat.getActionView(menuItem);
        //显示搜索框
        //searchView.setIconified(false);
        //显示搜索框，且其不能被隐藏
        searchView.setIconifiedByDefault(false);
        //显示提交按钮，这里可以获取到id，设置自定义图片
        ImageView icon = (ImageView) searchView.findViewById(R.id.search_go_btn);
        icon.setImageResource(R.mipmap.ic_launcher);
        icon.setVisibility(View.VISIBLE);
        //设置监听
        icon.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(MainActivity.this, searchView.getQuery(), Toast.LENGTH_SHORT).show();
            }
        });
        //获取id，从而设置提示
        EditText edit = (EditText) searchView.findViewById(R.id.search_src_text);
        edit.setHint("请输入搜索的内容");
        
        searchView.setSubmitButtonEnabled(true);
        //SearchView还有很多设置监听选项，例如提交监听，文本监听

        return true;
    }
}

效果如下：

Toolbar

顶部导航栏。用于显示标题，返回，菜单等，最开始是使用的ActionBar
由于ActionBar的种种使用不便，再加上拓展性差，google后来推出了Toolbar，为了增强其功能，现在还有APPbar可供使用
首先还是要把主题设置为NoActionBar

<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>
    </style>

</resources>

然后使用Toolbar布局，由于ToolBar继承自ViewGroup，所以其是一个容器

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        app:logo="@mipmap/ic_launcher"
        app:navigationIcon="@drawable/abc_ic_ab_back_material"
        app:subtitle="子标题"
        app:subtitleTextColor="@android:color/white"
        app:title="主标题"
        app:titleTextColor="@color/colorAccent">
        <!--<TextView-->
        <!--android:layout_width="wrap_content"-->
        <!--android:layout_height="wrap_content"-->
        <!--android:layout_gravity="center"-->
        <!--android:text="这里是标题"/>-->
    </android.support.v7.widget.Toolbar>

</LinearLayout>

最后设置Toolbar到活动，并设置监听

public class MainActivity extends AppCompatActivity {

    private Toolbar toolbar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });
    }
}

测试效果如下

接下来实现Toolbar的隐藏效果
这样的效果实现思路就是Toolbar在上层，后面的布局在下层，后面的布局设置padding，然后再滑动过程中监听滑动距离，设置Toolbar的透明度

interface TranslucentListener {
    //透明度的回调监听 alpha:0~1
    void onTranlucent(float alpha);
}

自定义ScrollView，在onScrollChanged()中监听

public class MyScrollView extends ScrollView {
    private TranslucentListener translucentListener;

    public void setTranslucentListener(TranslucentListener translucentListener) {
        this.translucentListener = translucentListener;
    }

    public MyScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onScrollChanged(int l, int t, int oldl, int oldt) {
        super.onScrollChanged(l, t, oldl, oldt);
        if (translucentListener != null) {
            Log.d("cj5785", "onScrollChanged");
            int scrollY = getScrollY();
            int screen_height = getContext().getResources().getDisplayMetrics().heightPixels;
            //滑出1/3时候完全透明
            if (scrollY <= screen_height / 3f) {
                translucentListener.onTranlucent(1 - scrollY / (screen_height / 3f));
            }
        }
    }
}

最后在活动中回调

public class MainActivity extends AppCompatActivity implements TranslucentListener{

    private Toolbar toolbar;
    private MyScrollView scrollView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });
        scrollView = findViewById(R.id.scroll_view);
        scrollView.setTranslucentListener(this);
    }

    @Override
    public void onTranlucent(float alpha) {
        toolbar.setAlpha(alpha);
    }
}

贴出布局
android:clipToPadding="false" 该控件的绘制范围是否不在Padding里面。false：绘制的时候范围会考虑padding即会往里面缩进
android:clipChildren="false" 子控件是否能不超出padding的区域（比如ScrollView上滑动的时候，child可以滑出该区域）

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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">

    <com.cj5785.toolbartest.MyScrollView
        android:id="@+id/scroll_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clipChildren="false"
        android:clipToPadding="false"
        android:paddingTop="?attr/actionBarSize">

        <android.support.v7.widget.LinearLayoutCompat
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

            <TextView
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:background="@android:color/holo_orange_light" />

            <TextView
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:background="@android:color/holo_green_light" />

            <TextView
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:background="@android:color/holo_blue_light" />

            <TextView
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:background="@android:color/holo_red_light" />

            <TextView
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:background="@android:color/holo_purple" />


        </android.support.v7.widget.LinearLayoutCompat>
    </com.cj5785.toolbartest.MyScrollView>

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:logo="@mipmap/ic_launcher"
        app:navigationIcon="@drawable/abc_ic_ab_back_material"
        app:subtitle="子标题"
        app:subtitleTextColor="@android:color/white"
        app:title="主标题"
        app:titleTextColor="@color/colorAccent">
        <!--<TextView-->
        <!--android:layout_width="wrap_content"-->
        <!--android:layout_height="wrap_content"-->
        <!--android:layout_gravity="center"-->
        <!--android:text="这里是标题"/>-->
    </android.support.v7.widget.Toolbar>

</RelativeLayout>

实现效果：

CoordinatorLayout

监听滑动控件的滑动通过Behavior反馈到其他子控件并执行一些动画
这里的滑动控件指的是RecyclerView/NestedScrollView/ViewPager，意味着ListView、ScrollView不行
使用前需要添加support-design依赖

implementation 'com.android.support:design:25.4.0'

布局

<?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.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <android.support.design.widget.FloatingActionButton
        app:layout_behavior=".FABBehavior"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_margin="16dp" />

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

适配器

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {

    private List<String> list;

    class MyViewHolder extends RecyclerView.ViewHolder {
        private TextView textView;

        public MyViewHolder(View itemView) {
            super(itemView);
            textView = (TextView) itemView.findViewById(android.R.id.text1);
        }
    }

    public MyAdapter(List<String> list) {
        this.list = list;
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
        View view = layoutInflater.inflate(android.R.layout.simple_list_item_1,parent,false);
        MyViewHolder holder = new MyViewHolder(view);
        return holder;
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, int position) {
        holder.textView.setText(list.get(position));
    }

    @Override
    public int getItemCount() {
        return list.size();
    }
}

Behavior

public class FABBehavior extends FloatingActionButton.Behavior {

    private boolean isShow;

    public FABBehavior(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    //依赖滑动开始回调
    @Override
    public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child, View directTargetChild, View target, int nestedScrollAxes) {
        //nestedScrollAxes 滑动的方向，这里我们依赖recyclerview，只关心其是否垂直滑动
        return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL
                || super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);
    }

    //依赖滑动过程回调
    @Override
    public void onNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
        //根据情况执行动画
        if (dyConsumed > 0 && isShow) {
            isShow = false;
            onHide(child);
        } else if (dyConsumed < 0) {
            isShow = true;
            onShow(child);
        }
    }

    private void onShow(FloatingActionButton fab) {
        ViewCompat.animate(fab).scaleX(1f).scaleY(1f).start();
    }

    private void onHide(FloatingActionButton fab) {
        ViewCompat.animate(fab).scaleX(0f).scaleY(0f).start();
    }
}

调用

public class MainActivity extends AppCompatActivity {
    private List<String> list = new ArrayList<>();
    private RecyclerView recyclerView;
    private MyAdapter adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        for (int i = 0; i < 100; i++) {
            list.add("item " + i);
        }
        adapter = new MyAdapter(list);
        recyclerView.setAdapter(adapter);
    }
}

效果如下，实现了FloatingActionButton上划隐藏，下拉显示

AppBarLayout

AppBarLayout继承自LinearLayout，一般用于导航栏，其常见子控件为Toolbar，但同时又不局限于Toolbar，可以实现导航栏的多种综合效果，其作为容器，里面可以增加布局，按照需要去实现各种效果
这里做一个简单的演示，导航栏通过recyclerview的滑动而显隐的效果
首先依旧是要引入依赖

implementation 'com.android.support:design:25.4.0'

然后编写布局，其外层为CoordinatorLayout，这里使用了预设behavior：appbar_scrolling_view_behavior，在监听的控件加上Flag设置，例如这里的app:layout_scrollFlags="scroll|enterAlways""
其Flag参数包括
scroll:将此布局和滚动时间关联。这个标识要设置在其他标识之前，没有这个标识则布局不会滚动且其他标识设置无效
enterAlways:任何向下滚动操作都会使此布局可见。这个标识通常被称为快速返回模式
enterAlwaysCollapsed：假设你定义了一个最小高度（minHeight）同时enterAlways也定义了，那么view将在到达这个最小高度的时候开始显示，并且从这个时候开始慢慢展开，当滚动到顶部的时候展开完
exitUntilCollapsed：当你定义了一个minHeight，此布局将在滚动到达这个最小高度的时候折叠
snap:当一个滚动事件结束，如果视图是部分可见的，那么它将被滚动到收缩或展开。例如，如果视图只有底部25%显示，它将折叠。相反，如果它的底部75%可见，那么它将完全展开
snap：

<?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.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clipChildren="false"
        android:clipToPadding="false"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

    <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"
            android:layout_height="?attr/actionBarSize"
            android:layout_gravity="center"
            android:background="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|enterAlways"
            app:title="这是标题" />
    </android.support.design.widget.AppBarLayout>

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

由于使用的是RecyclerView，故还需要适配器

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
    private List<String> list;

    class MyViewHolder extends RecyclerView.ViewHolder {
        private TextView textView;

        public MyViewHolder(View itemView) {
            super(itemView);
            textView = (TextView) itemView.findViewById(android.R.id.text1);
        }
    }

    public MyAdapter(List<String> list) {
        this.list = list;
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
        View view = layoutInflater.inflate(android.R.layout.simple_list_item_1,parent,false);
        MyViewHolder holder = new MyViewHolder(view);
        return holder;
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, int position) {
        holder.textView.setText(list.get(position));
    }

    @Override
    public int getItemCount() {
        return list.size();
    }
}

设置RecyclerView数据

public class MainActivity extends AppCompatActivity {
    private List<String> list = new ArrayList<>();
    private MyAdapter adapter;
    private RecyclerView recyclerView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        for (int i = 0; i < 30; i++) {
            list.add("item " + i);
        }
        adapter = new MyAdapter(list);
        recyclerView.setAdapter(adapter);
    }
}

查看效果如下

ViewPager + TabLayout + Fragment + AppBarLayout

AppBarLayout同时还可以使用其他可滑动控件，例如NestedScrollView，其常用组合为：ViewPager + TabLayout + Fragment + AppBarLayout
由于这套组合的体验效果不错，这里展现一下这个样式的demo
首先依旧是引入依赖

因为使用了Toolbar，所以这里使用NoActionBar的主题

<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>
    </style>

</resources>

编写ViewPager的Fragment布局，这里简单显示text，记得这里应该是一个滑动控件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical">

    <android.support.v4.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <TextView
            android:id="@+id/text_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:textColor="@android:color/black"
            android:textSize="24sp" />
    </android.support.v4.widget.NestedScrollView>
</LinearLayout>

然后是自定义的fragment

public class DefaultFragment extends Fragment {
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_layout,container,false);
        TextView textView = (TextView) view.findViewById(R.id.text_view);
        Bundle bundle = getArguments();
        String title = bundle.getString("title");
        textView.setText(title+"\n\n");
        for (int i = 0; i < 10; i++) {
            textView.append("这是一个ViewPager + TabLayout + Fragment + AppBarLayout测试用例\n\n");
        }
        return view;
    }
}

接下来是主布局

<?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"
    android:orientation="vertical"
    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"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|enterAlways"
            app:title="标题" />

        <android.support.design.widget.TabLayout
            android:id="@+id/table_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@android:color/holo_orange_light"
            app:tabGravity="fill"
            app:tabMode="scrollable" />
    </android.support.design.widget.AppBarLayout>

    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

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

最后关联TableLayout和ViewPager

public class MainActivity extends AppCompatActivity {

    private TabLayout tabLayout;
    private ViewPager viewPager;
    private String[] title = {
            "新闻", "体育", "汽车", "科技", "手机", "数码", "读书", "艺术"
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tabLayout = (TabLayout) findViewById(R.id.table_layout);
        viewPager = (ViewPager) findViewById(R.id.view_pager);
        MyPagerAdapter adapter = new MyPagerAdapter(getSupportFragmentManager());
        viewPager.setAdapter(adapter);
        tabLayout.setupWithViewPager(viewPager);
    }

    class MyPagerAdapter extends FragmentPagerAdapter {

        public MyPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return title[position];
        }

        @Override
        public Fragment getItem(int position) {
            Fragment fragment = new DefaultFragment();
            Bundle bundle = new Bundle();
            bundle.putString("title", title[position]);
            fragment.setArguments(bundle);
            return fragment;
        }

        @Override
        public int getCount() {
            return title.length;
        }
    }
}

这样就完成了显示功能

CollapsingToolbarLayout

这个控件可以实现Toolbar的折叠效果
先看下其常用参数
expandedTitleMargin：展开后的边距
statusBarScrim：状态栏颜色
contentScrim：内容颜色
app:layout_collapseMode：设置折叠模式，分为视差模式(parallax:在折叠的时候会有折叠视差效果，一般搭配layout_collapseParallaxMultiplier，视差的明显程度)，固定模式(pin：在折叠的时候最后固定在顶端，再和toolbar一起推出)，无模式(none：折叠时toolbar直接推出)
expandedTitleGravity：展开的位置
collapsedTitleGravity：折叠的位置
使用时依然需要导入依赖

implementation 'com.android.support:design:25.4.0'

然后使用NoActionBar主题
使用时的布局示例

<?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.v4.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <TextView
            android:id="@+id/text_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="@string/test_text"
            android:textColor="@android:color/black"
            android:textSize="24sp" />
    </android.support.v4.widget.NestedScrollView>

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="180dp">

        <android.support.design.widget.CollapsingToolbarLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            app:expandedTitleMargin="8dp"
            app:statusBarScrim="?attr/colorPrimary"
            app:contentScrim="?attr/colorPrimary"
            app:expandedTitleGravity="center"
            app:collapsedTitleGravity="center"
            app:title="现代诗歌欣赏">

            <ImageView
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:scaleType="centerCrop"
                android:src="@drawable/tdj"
                app:layout_collapseMode="parallax"
                app:layout_collapseParallaxMultiplier="0.5"/>

            <android.support.v7.widget.Toolbar
                app:layout_collapseMode="pin"
                android:id="@+id/tool_bar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="?attr/colorPrimary"/>
        </android.support.design.widget.CollapsingToolbarLayout>
    </android.support.design.widget.AppBarLayout>

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

设置Toolbar

public class MainActivity extends AppCompatActivity {
    private Toolbar toolbar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        toolbar = (Toolbar) findViewById(R.id.tool_bar);
        toolbar.setNavigationIcon(R.mipmap.ic_launcher);
        setSupportActionBar(toolbar);
    }
}

实现的效果如下图