Is there an alternative to NestedScrollView for use with a WebView?

问题

When using a WebView inside a NestedScrollView there are a few issues. The main one I'm fighting is that sites which load more content as you scroll down don't work well, for example vimeo.com. Also setting the view to LAYER_TYPE_HARDWARE doesn't work, probably for the same reason, it basically crashes because of the height. So, is there an alternative to the NestedScrollView if I want to use CoordinatorLayout in order to collapse the toolbar when the user scrolls inside the WebView?

My code is below. In order to reproduce the issue just load vimeo.com and scroll to the bottom.

activity_scrolling.xml

    <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">

            <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>

    <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="com.webviewnestedscroll.ScrollingActivity"
        tools:showIn="@layout/activity_scrolling">

        <WebView
            android:id="@+id/webview"
            android:layout_width="match_parent"
            android:layout_height="match_parent"></WebView>
    </android.support.v4.widget.NestedScrollView>

    <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"
        android:src="@android:drawable/ic_dialog_email"
        app:layout_anchor="@id/app_bar"
        app:layout_anchorGravity="bottom|end"/>

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

ScrollingActivity.java

package com.webviewnestedscroll;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class ScrollingActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_scrolling);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        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();
            }
        });
        WebView view = (WebView) findViewById(R.id.webview);
        view.setWebViewClient(new WebViewClient());
        WebSettings settings = view.getSettings();
        settings.setJavaScriptEnabled(true);
        settings.setAllowContentAccess(true);
        settings.setAppCacheEnabled(true);
        settings.setDatabaseEnabled(true);
        settings.setDomStorageEnabled(true);
        settings.setRenderPriority(WebSettings.RenderPriority.HIGH);
        settings.setJavaScriptEnabled(true);
        settings.setSupportZoom(true);
        settings.setJavaScriptCanOpenWindowsAutomatically(true);
        settings.setBuiltInZoomControls(true);
        settings.setAppCacheEnabled(true);
        settings.setAppCachePath(getCacheDir().getAbsolutePath());
        settings.setDatabaseEnabled(true);
        settings.setSupportMultipleWindows(true);
        settings.setLoadWithOverviewMode(true);
        settings.setUseWideViewPort(true);
        settings.setDomStorageEnabled(true);
        settings.setAllowContentAccess(true);
        settings.setAllowFileAccess(true);
        settings.setSaveFormData(true);
        //view.setLayerType(View.LAYER_TYPE_HARDWARE, null);

        view.loadUrl("http://vimeo.com");



    }

    @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_scrolling, menu);
        return true;
    }

    @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();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

EDIT: Forgot to mention, I've already tried wrapping it around a FrameLayout, LinearLayout, RelativeLayout, etc. I've also tried setting the sizes to a specific number.

回答1:

As i referred, You should try to add LinearLayout with android:descendantFocusability="blocksDescendants" like:

<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="com.webviewnestedscroll.ScrollingActivity"
        tools:showIn="@layout/activity_scrolling">

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

        <WebView
            android:id="@+id/webview"
            android:layout_width="match_parent"
            android:layout_height="match_parent"></WebView>

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

May it will helpful to you. Thanks.

来源：https://stackoverflow.com/questions/34933091/is-there-an-alternative-to-nestedscrollview-for-use-with-a-webview