常用的Toolbar+viewpager汇总（二）

本文基于常用的Toolbar+viewpager汇总（一）进行修改

下载链接：https://share.weiyun.com/5IHvE0K

public class MainActivity extends AppCompatActivity {

    private TabLayout tableLayout;
    private ViewPager viewPager;
    List<Fragment> list_fragment = new ArrayList<>();
    private TabAdapter tabAdapter;
    String[] favourites = {"页面一", "页面二", "页面三"};
    private Toolbar toolbar;
    private AppBarLayout appBarLayout;
    private CollapsingToolbarLayout collapsingToolbarLayout;
    private ImageView imageView;

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

    private void initData() {
        list_fragment.add(new DemoFragment());
        list_fragment.add(new DemoFragment());
        list_fragment.add(new DemoFragment());
        tabAdapter = new TabAdapter(getSupportFragmentManager());
        tableLayout.setupWithViewPager(viewPager);
        viewPager.setAdapter(tabAdapter);

        appBarLayout.addOnOffsetChangedListener(new AppBarStateChangeListener() {
            @Override
            public void onStateChanged(AppBarLayout appBarLayout, State state) {
                if( state == State.EXPANDED ) {
                    //展开状态
                    toolbar.setBackgroundColor(Color.argb((int) 0, 0, 0, 0));
                }else if(state == State.COLLAPSED){
                    //折叠状态
                    toolbar.setBackgroundColor(Color.argb((int) 255, 255, 255, 255));
                }else {
                    //中间状态
                    toolbar.setBackgroundColor(Color.argb((int) 0, 0, 0, 0));
                }
                collapsingToolbarLayout.setTitle("标题");
                collapsingToolbarLayout.setCollapsedTitleGravity(Gravity.CENTER);
            }
        });
    }

    class TabAdapter extends FragmentPagerAdapter {
        public TabAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            return list_fragment.get(position);
        }

        @Override
        public int getCount() {
            return list_fragment.size();
        }

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

    private void initView() {
        tableLayout = (TabLayout) findViewById(R.id.tabs);
        viewPager = (ViewPager) findViewById(R.id.viewpager);
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        appBarLayout = (AppBarLayout) findViewById(R.id.app_bar);
        collapsingToolbarLayout = (CollapsingToolbarLayout) findViewById(R.id.toolbar_layout);
        imageView = (ImageView) findViewById(R.id.iv);

    }
}

新增类

public abstract class AppBarStateChangeListener implements AppBarLayout.OnOffsetChangedListener {

    public enum State {
        EXPANDED,
        COLLAPSED,
        IDLE
    }

    private State mCurrentState = State.IDLE;

    @Override
    public final void onOffsetChanged(AppBarLayout appBarLayout, int i) {
        if (i == 0) {
            if (mCurrentState != State.EXPANDED) {
                onStateChanged(appBarLayout, State.EXPANDED);
            }
            mCurrentState = State.EXPANDED;
        } else if (Math.abs(i) >= appBarLayout.getTotalScrollRange()) {
            if (mCurrentState != State.COLLAPSED) {
                onStateChanged(appBarLayout, State.COLLAPSED);
            }
            mCurrentState = State.COLLAPSED;
        } else {
            if (mCurrentState != State.IDLE) {
                onStateChanged(appBarLayout, State.IDLE);
            }
            mCurrentState = State.IDLE;
        }
    }

    public abstract void onStateChanged(AppBarLayout appBarLayout, State state);
}

<?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"
    android:orientation="vertical"
    tools:context="com.sloop.tabdemo.MainActivity">

    <android.support.design.widget.CoordinatorLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <android.support.design.widget.AppBarLayout
            android:id="@+id/app_bar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="#fff"
            android:fitsSystemWindows="true"
            app:elevation="0dp">

            <android.support.design.widget.CollapsingToolbarLayout
                android:id="@+id/toolbar_layout"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:fitsSystemWindows="true"
                app:collapsedTitleTextAppearance="@style/collapsedStyle"
                app:expandedTitleTextAppearance="@style/expandedStyle"
                app:layout_scrollFlags="scroll|exitUntilCollapsed">

                <RelativeLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    app:layout_scrollFlags="scroll">

                    <ImageView
                        android:id="@+id/iv"
                        android:layout_width="match_parent"
                        android:layout_height="280dp"
                        android:scaleType="fitXY"
                        android:src="@drawable/img" />

                </RelativeLayout>

                <android.support.v7.widget.Toolbar
                    android:id="@+id/toolbar"
                    android:layout_width="match_parent"
                    android:layout_height="?attr/actionBarSize"
                    app:contentInsetLeft="0dp"
                    app:contentInsetStart="0dp"
                    app:layout_collapseMode="pin">

                </android.support.v7.widget.Toolbar>
            </android.support.design.widget.CollapsingToolbarLayout>

            <android.support.design.widget.TabLayout
                android:id="@+id/tabs"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="center"
                app:tabIndicatorHeight="3dp"
                app:tabSelectedTextColor="#f00"
                app:tabTextColor="#000" />

            <View
                android:layout_width="match_parent"
                android:layout_height="1dp"
                android:background="#25979797" />

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

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            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:overScrollMode="never" />
        </RelativeLayout>

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


</LinearLayout>