仿淘宝继续上拉进入商品详情页的效果，双Fragment实现；

动画效果：

slide_above_in.xml

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

<set xmlns:android="http://schemas.android.com/apk/res/android">

    <translate

        android:fromYDelta="-100%p"

        android:toYDelta="0%p"

        android:duration="300"/>

    <alpha

        android:fromAlpha="0.5"

        android:toAlpha="1.0"

        android:duration="300"/>

</set>

slide_above_out.xml

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

<set xmlns:android="http://schemas.android.com/apk/res/android">

    <translate

        android:toYDelta="-100%p"

        android:fromXDelta="0%p"

        android:duration="300"/>

    <alpha

        android:fromAlpha="1.0"

        android:toAlpha="0.5"

        android:duration="300"/>

</set>

slide_below_in.xml

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

<set xmlns:android="http://schemas.android.com/apk/res/android">

    <translate

        android:fromYDelta="100%p"

        android:toYDelta="0%p"

        android:duration="300"/>

    <alpha

        android:fromAlpha="0.5"

        android:toAlpha="1.0"

        android:duration="300"/>

</set>

slide_below_out.xml

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

<set xmlns:android="http://schemas.android.com/apk/res/android">

    <translate

        android:toYDelta="100%p"

        android:fromYDelta="0%p"

        android:duration="300"/>

    <alpha

        android:toAlpha="0.5"

        android:fromAlpha="1.0"

        android:duration="300"/>

</set>

代码：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private FrameLayout fl;

    private AboveFragment AF;

    private BelowFragment BF;

    private Button btn;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_double_fragment);

        fl = (FrameLayout) findViewById(R.id.fl);

        btn = (Button) findViewById(R.id.qiehuan);

        btn.setOnClickListener(this);

        AF = new AboveFragment();

        BF = new BelowFragment();

        initList(); //先给Fragment设置监听

        getSupportFragmentManager().beginTransaction().add(R.id.fl,AF).commit();

    }

    private void initList() {

        AF.setContinueSlideScrollView(new ContinueSlideScrollView.onContinueSlide() {

            @Override

            public void onContinueSlideTop() {

            }

            @Override

            public void onContinueSlideBottom() {

                if (BF.isAdded()){

                    getSupportFragmentManager().beginTransaction().setCustomAnimations(R.anim.slide_below_in,R.anim.slide_below_out).show(BF).commit();

                }else{

                    getSupportFragmentManager().beginTransaction()

                            .setCustomAnimations(R.anim.slide_below_in,R.anim.slide_below_out)

                            .add(R.id.fl,BF).commit();

                }

                getSupportFragmentManager().beginTransaction()

                        .setCustomAnimations(R.anim.slide_above_in,R.anim.slide_above_out)

                        .hide(AF).commit();

            }

        });

        BF.setContinueSlideScrollView(new ContinueSlideScrollView.onContinueSlide() {

            @Override

            public void onContinueSlideTop() {

                if (AF.isAdded()){

                    getSupportFragmentManager().beginTransaction()

                            .setCustomAnimations(R.anim.slide_above_in,R.anim.slide_above_out)

                            .show(AF).commit();

                }else{

                    getSupportFragmentManager().beginTransaction()

                            .setCustomAnimations(R.anim.slide_above_in,R.anim.slide_above_out)

                            .add(R.id.fl,AF).commit();

                }

                getSupportFragmentManager().beginTransaction()

                        .setCustomAnimations(R.anim.slide_below_in,R.anim.slide_below_out)

                        .hide(BF).commit();

            }

            @Override

            public void onContinueSlideBottom() {

            }

        });

    }

    @Override

    public void onClick(View view) {

        if ("0".equals(btn.getTag().toString())){

            btn.setTag("1");

            if (BF.isAdded()){

                getSupportFragmentManager().beginTransaction().setCustomAnimations(R.anim.slide_below_in,R.anim.slide_below_out).show(BF).commit();

            }else{

                getSupportFragmentManager().beginTransaction()

                        .setCustomAnimations(R.anim.slide_below_in,R.anim.slide_below_out)

                        .add(R.id.fl,BF).commit();

            }

            getSupportFragmentManager().beginTransaction()

                    .setCustomAnimations(R.anim.slide_above_in,R.anim.slide_above_out)

                    .hide(AF).commit();

        }else{

            btn.setTag("0");

            if (AF.isAdded()){

                getSupportFragmentManager().beginTransaction()

                        .setCustomAnimations(R.anim.slide_above_in,R.anim.slide_above_out)

                        .show(AF).commit();

            }else{

                getSupportFragmentManager().beginTransaction()

                        .setCustomAnimations(R.anim.slide_above_in,R.anim.slide_above_out)

                        .add(R.id.fl,AF).commit();

            }

            getSupportFragmentManager().beginTransaction()

                    .setCustomAnimations(R.anim.slide_below_in,R.anim.slide_below_out)

                    .hide(BF).commit();

        }

    }

}

其中 initList() 函数是我定义的ScrollView滑动到底部再继续滑动的监听，https://mp.csdn.net/postedit/85257597

项目这个Demo已上传Github：https://github.com/CuiChenbo/DoubleFragmentSwitch