CoordinatorLayout：android之ScrollingActivity

1.效果图

2.新建SrcollingActivity后生成代码为：

<?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:fitsSystemWindows="true"
    tools:context="myapplication.com.myceshi.ScrollingActivity">

    <android.support.design.widget.AppBarLayout android:id="@+id/app_bar"
        android:layout_width="match_parent" android:layout_height="@dimen/app_bar_height"
        android:fitsSystemWindows="true" android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.design.widget.CollapsingToolbarLayout android:id="@+id/toolbar_layout"
            android:layout_width="match_parent" android:layout_height="match_parent"
            android:fitsSystemWindows="true" app:contentScrim="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|exitUntilCollapsed">

            <ImageView
                android:layout_width="match_parent"
                android:scaleType="centerCrop"
                android:layout_height="match_parent"
                android:src="@mipmap/a"/>
            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:layout_collapseMode="pin"
                app:popupTheme="@style/AppTheme.PopupOverlay" />

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

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

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="@dimen/fab_margin"
        app:layout_anchor="@id/app_bar"
        app:layout_anchorGravity="bottom|end"
        app:srcCompat="@android:drawable/ic_dialog_email" />

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

3.主要内容布局是

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView
    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" app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="myapplication.com.myceshi.ScrollingActivity"
    tools:showIn="@layout/activity_scrolling">


    <LinearLayout
        android:layout_height="match_parent"
        android:layout_width="match_parent"
        android:orientation="vertical">
    
            <TextView
                android:layout_width="match_parent"
                android:layout_height="60dp"
                android:lineSpacingExtra="4dp"
                android:textSize="20dp"
                android:text="内容”
                android:textColor="@color/colorAccent"/>
          
     
    </LinearLayout>

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

4.onCreate

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_scrolling);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
　　　　// 设置返回键和菜单栏可用，可见
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeButtonEnabled(true);
        /**
         * 悬浮球点击事件
         * */
        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
    }

  @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        /**
         *
         * 菜单set事件
         * */
        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            Toast.makeText(getApplicationContext(),"setting1",Toast.LENGTH_SHORT).show();
            return true;
        }
        /**
         * 菜单set事件
         * */
        if (id == R.id.action_set) {
            Toast.makeText(getApplicationContext(),"Setting2",Toast.LENGTH_SHORT).show();

            return true;
        }
        /**
         * 返回键事件
         * */
        if(id==android.R.id.home){
            Toast.makeText(getApplicationContext(),"返回键",Toast.LENGTH_SHORT).show();
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

 @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_detail_, menu);
        return true;
    }

<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="myapplication.com.myplattvok.avtivity.Detail_Activity">
    <item
        android:id="@+id/action_settings"
        android:orderInCategory="100"
        android:title="@string/action_settings"
        app:showAsAction="never" />
</menu>