一旦CollapsingToolbarLayout折叠，NestedScrollView就会停止滚动

Question

首先让我澄清一下，我发现了一些与此问题类似的问题，但没有一个对我有用。

因此，我有一个活动（MainActivity.java），该活动具有底部导航选项卡，每个选项卡都有其自己的片段，第三个片段名为“ ServiceFragment.java”（也是底部导航中的第三个选项卡）。

类别：

ServiceFragment.java

package in.ikleen.ikleenservices;

import android.content.Context;
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class ServiceFragment extends Fragment {

    Context context;

    public ServiceFragment() {
        // Required empty public constructor
    }

    @Override
    public void onAttach (Context context){
        super.onAttach(context);
        this.context = context;
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View rootView = inflater.inflate(R.layout.fragment_service, container, false);

        ViewPager viewPager = rootView.findViewById(R.id.service_view_pager);
        viewPager.setOffscreenPageLimit(3);
        TabLayout tabLayout = rootView.findViewById(R.id.service_tab_layout);
        ServiceFragmentPageAdapter pageAdapter = new ServiceFragmentPageAdapter(context, getChildFragmentManager());
        viewPager.setAdapter(pageAdapter);
        tabLayout.setupWithViewPager(viewPager);

        return rootView;
    }

}

ServiceFragmentPageAdapter.java

package in.ikleen.ikleenservices;

import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;

public class ServiceFragmentPageAdapter extends FragmentPagerAdapter {
    private Context mContext;
    Fragment zero, first, second;

    public ServiceFragmentPageAdapter (Context context, FragmentManager fm){
        super(fm);
        mContext = context;
        zero = new WashDryServiceFragment();
        first = new WashDryIronServiceFragment();
        second = new AdditionalProductsServiceFragment();
    }

    @Override
    public Fragment getItem(int position){
        switch (position){
            case 0:
                return zero;
            case 1:
                return first;
            case 2:
                return second;
            default:
                return zero;
        }
    }

    @Override
    public int getCount(){
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position){
        switch (position){
            case 0:
                return mContext.getString(R.string.wash_dry);
            case 1:
                return mContext.getString(R.string.wash_dry_iron);
            case 2:
                return mContext.getString(R.string.additional_products);
            default:
                return mContext.getString(R.string.wash_dry);
        }
    }
}

WashDryServiceFragment.java（viewpager选项卡布局的第一个选项卡，也是一个有问题的选项卡）

package in.ikleen.ikleenservices;


import android.annotation.TargetApi;
import android.os.Bundle;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CollapsingToolbarLayout;
import android.support.design.widget.CoordinatorLayout;
import android.support.v4.app.Fragment;
import android.support.v4.widget.NestedScrollView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.Toolbar;

import java.lang.annotation.Target;
import java.util.ArrayList;
import java.util.List;

public class WashDryServiceFragment extends Fragment {


    public WashDryServiceFragment() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View rootView = inflater.inflate(R.layout.fragment_wash_dry_service, container, false);

        ListView listView = (ListView) rootView.findViewById(R.id.listViewWashDryService);

        ArrayList<String> stringList = new ArrayList<>();
        for(int i=0; i<20; i++) {
            stringList.add("Hello");
        }

        ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, stringList);
        listView.setAdapter(adapter);

        //TESTED BELOW CODE BUT CANNOT EVEN SCROLL A LITTLE BIT SO COMMENTED IT
        //Toolbar toolbar = (Toolbar) rootView.findViewById(R.id.toolbar1);
        //NestedScrollView nestedScrollView = (NestedScrollView) rootView.findViewById(R.id.nestedScroll);
        //CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) nestedScrollView.getLayoutParams();
        //params.setBehavior(new ConstrainedScrollBehavior());

        return rootView;
    }

}

布局：

fragment_service.xml

<FrameLayout 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"
    tools:context="in.ikleen.ikleenservices.ServiceFragment">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <android.support.design.widget.TabLayout
            android:id="@+id/service_tab_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:tabTextAppearance="@style/Base.TextAppearance.AppCompat.Small"
            app:tabMode="fixed"/>

        <android.support.v4.view.ViewPager
            android:id="@+id/service_view_pager"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>

    </LinearLayout>

</FrameLayout>

Fragment_wash_dry_service.xml（问题所在）

<FrameLayout 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"
    tools:context="in.ikleen.ikleenservices.WashDryServiceFragment">

    <android.support.design.widget.CoordinatorLayout
        android:id="@+id/coordinatorlayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <android.support.design.widget.AppBarLayout
            android:id="@+id/appBarLayout"
            android:layout_width="match_parent"
            android:layout_height="150dp"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

            <android.support.design.widget.CollapsingToolbarLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:layout_scrollFlags="scroll|exitUntilCollapsed">

                <ImageView
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:layout_gravity="center_horizontal"
                    app:layout_collapseMode="parallax"
                    android:scaleType="centerInside"
                    app:layout_collapseParallaxMultiplier="0.5"
                    app:layout_scrollFlags="scroll|exitUntilCollapsed"
                    android:src="@mipmap/ld_00"/>

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

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

        <android.support.v4.widget.NestedScrollView
            android:id="@+id/nestedScroll"
            android:layout_width="fill_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true"
            android:fillViewport="true"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            android:layout_gravity="fill_vertical">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:clickable="true"
                android:orientation="vertical">

                <ListView
                    android:id="@+id/listViewWashDryService"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:layout_below="@+id/appBarLayout"/>

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="JUST FOR TESTS"
                    android:textAppearance="@style/TextAppearance.AppCompat.Large"/>

            </LinearLayout>

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

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

</FrameLayout>

谢谢

Answer 1

在这种情况下的问题是：（ps我很愚蠢）

listview无法在nestedscrollview内滚动，因此，当collapsingtoolbar折叠时，由于nestedscrollview已经填满了父级，因此没有必要对其进行更多滚动，并且listview仍然无法滚动。 （我知道，愚蠢的解释）

解：

1：要么删除nestedscrollview内的listview

要么

2：在android:nestedScrollingEnabled="true"添加此属性android:nestedScrollingEnabled="true" （未经测试，但应该可以使用）