CollapsingToolbarLayout的使用

 <!-- layout_collapseMode(折叠模式)-有两个值:                 1.parallax:在内容滚动时，CollapsingToolbarLayout中的View（比如ImageView)也可以同时滚动，                 实现视差滚动效果，通常和layout_collapseParallaxMultiplier(设置视差因子)搭配使用。                 2.pin - 当CollapsingToolbarLayout完全收缩后，Toolbar还可以固定在屏幕上。          -->

<?xml version="1.0" encoding="utf-8"?><android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:orientation="vertical"    tools:context="fanggao.qf.collapsingtoolbarlayout.MainActivity">   <!-- android:fitsSystemWindow = "true" 表示整个布局展示是整个屏幕出去状态栏,标题栏和导航栏剩下的区域-->    <android.support.design.widget.AppBarLayout        android:id="@+id/layout_appbar"        android:layout_width="match_parent"        android:layout_height = "wrap_content"       >        <!--         app:expandedTitleMarginStart="10dp"        设置扩张时候(还没有收缩时)title离屏幕左边的距离         app:contentScrim="?attr/colorPrimary"        设置当完全CollapsingToolbarLayout折叠(收缩)后的背景颜色        -->        <android.support.design.widget.CollapsingToolbarLayout            android:id="@+id/ctb"            android:layout_width="match_parent"            android:layout_height="250dp"            android:fitsSystemWindows="true"            app:contentScrim="?attr/colorPrimary"            app:expandedTitleMarginStart="10dp"            app:layout_scrollFlags="scroll|exitUntilCollapsed">               <ImageView            android:id="@+id/image"            android:layout_width="match_parent"            android:layout_height="match_parent"            android:scaleType="centerCrop"            app:layout_collapseMode="parallax"            android:src = "@drawable/cat"            />        <!--标题-->        <android.support.v7.widget.Toolbar            android:id="@+id/toolbar"            android:layout_width="match_parent"            android:layout_height="30dp"            app:layout_collapseMode="pin"            app:title="Toolbar"/>        </android.support.design.widget.CollapsingToolbarLayout>        <!--选项卡-->        <android.support.design.widget.TabLayout            android:id="@+id/tabLayout"            android:layout_width="match_parent"            android:layout_height="wrap_content"            app:tabIndicatorColor="@color/colorAccent"            app:tabMode="scrollable"            app:tabSelectedTextColor="@color/colorAccent"            app:tabTextColor="@android:color/black"/>    </android.support.design.widget.AppBarLayout>    <android.support.v4.widget.NestedScrollView        android:id="@+id/nestedScrollView"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:fillViewport="true"        app:layout_behavior="@string/appbar_scrolling_view_behavior">        <android.support.v4.view.ViewPager            android:id="@+id/viewPager"            android:layout_width="match_parent"            android:layout_height="wrap_content"/>    </android.support.v4.widget.NestedScrollView></android.support.design.widget.CoordinatorLayout>

public class MainActivity extends AppCompatActivity {    private Toolbar toolbar;    private ImageView image;    private ViewPager viewpager;    private TabLayout tabLayout;    private CollapsingToolbarLayout collapsingToolbarLayout;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();        initData();    }    private void initData() {        toolbar.setLogo(R.mipmap.ic_launcher);        setSupportActionBar(toolbar);        //设置返回按钮        getSupportActionBar().setDisplayHomeAsUpEnabled(true);        //设置收缩展开toolbar字体颜色        collapsingToolbarLayout.setExpandedTitleColor(Color.WHITE);        collapsingToolbarLayout.setCollapsedTitleTextColor(Color.BLACK);        //设置tablayout与viewPager        viewpager.setAdapter(new TestViewPageAdapter());        tabLayout.setupWithViewPager(viewpager);    }    private void initView() {        toolbar = (Toolbar) findViewById(R.id.toolbar);        image = (ImageView) findViewById(R.id.image);        viewpager = (ViewPager) findViewById(R.id.viewPager);       tabLayout = (TabLayout) findViewById(R.id.tabLayout);       collapsingToolbarLayout = (CollapsingToolbarLayout) findViewById(R.id.ctb);    }    class TestViewPageAdapter extends PagerAdapter{        @Override        public Object instantiateItem(ViewGroup container, int position) {            TextView textView = new TextView(MainActivity.this);            textView.setGravity(Gravity.CENTER);            textView.setText("pager "+(position+1));            textView.setTextSize(30);            textView.setTextColor(Color.BLUE);            container.addView(textView);            return textView;        }        @Override        public void destroyItem(ViewGroup container, int position, Object object) {            container.removeView((View)object);        }        @Override        public int getCount() {            return 5;        }        @Override        public boolean isViewFromObject(View view, Object object) {            return view == object;        }/*获得标题*/        /*该方法必须写,不然tablayout不能显示标题*/        @Override        public CharSequence getPageTitle(int position) {            return "TAB"+(position+1);        }    }}