How to prevent a scrollview from scrolling to a we

问题:

So I have a fascinating problem. Despite the fact that I'm not manually or programmatically scrolling my view, my WebView is being automatically scrolled to after the data inside it loads.

I've got a fragment in a viewpager. When I first load the pager, it works as expected and everything is shown. But once I "flip the page" the data loads and the WebView pops up to the top of the page, hiding the views above it, which is undesirable.

Does anyone know how to prevent this from happening?

My layout looks like such:

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@color/background" >

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

        <TextView
            android:id="@+id/article_title"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginRight="10dp"
            android:layout_marginLeft="10dp"
            android:layout_marginTop="10dp"
            android:layout_marginBottom="2dp"
            android:text="Some Title"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:textColor="@color/article_title"
            android:textStyle="bold" />

        <LinearLayout
            android:id="@+id/LL_Seperator"
            android:layout_width="fill_parent"
            android:layout_height="1dp"
            android:layout_marginLeft="10dp"
            android:layout_marginRight="10dp"
            android:layout_marginTop="5dp"
            android:layout_marginBottom="5dp"
            android:background="@color/text"
            android:orientation="horizontal" >
        </LinearLayout>

        <WebView
            android:id="@+id/article_content"
            android:layout_width="match_parent"
            android:layout_marginRight="10dp"
            android:layout_marginLeft="10dp"
            android:layout_height="wrap_content" />

        <TextView
            android:id="@+id/article_link"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="5dp"
            android:layout_marginTop="5dp"
            android:layout_marginRight="10dp"
            android:layout_marginLeft="10dp"
            android:text="View Full Article"
            android:textColor="@color/article_title"
            android:textStyle="bold" />
    </LinearLayout>

</ScrollView>

I'm also not giving focus to anything. By default, it seems to automatically scroll to the WebView after it has loaded. How do I prevent this?

回答1:

You can simply add this to your LinearLayout: android:focusableInTouchMode="true". It works for me.

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

回答2:

I had the same problem, after hours of trying several ideas, what finally worked for me was simply adding the descendantFocusability attribute to the ScrollView's containing LinearLayout, with the value blockDescendants. In your case:

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

Haven't had the problem reoccur since :)

回答3:

You should create new class extend ScrollView, then Override requestChildFocus:

public class MyScrollView extends ScrollView {

@Override 
public void requestChildFocus(View child, View focused) { 
    if (focused instanceof WebView ) 
       return;
    super.requestChildFocus(child, focused);
}
}

Then in your xml layout, using:

<MyScrollView 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@color/background" >

That works for me. The ScrollView will not auto scroll to the WebView anymore.

回答4:

Adding these line in main layout solves the problem

android:descendantFocusability="blocksDescendants"

回答5:

Like this:

<com.ya.test.view.MyScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:descendantFocusability="beforeDescendants"
        android:focusable="true"
        android:focusableInTouchMode="true" >

回答6:

Probably there are people who have the same problem I was having, so I'll help out.

I was trying to put android:descendantFocusability="beforeDescendants" in my main ScrollView as following:

<ScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:descendantFocusability="beforeDescendants">
    /*my linearlayout or whatever to hold the views */

and it wasn't working, so I had to make a RelativeLayout the parent of the ScrollView, and place the android:descendantFocusability="beforeDescendants" in the parent aswell.

So I solved it doing the following:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:descendantFocusability="blocksDescendants">

<ScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent">
/*my linearlayout or whatever to hold the views */

回答7:

I had to use the fully qualified name for MyScrollView, otherwise I got an inflate exception.

<com.mypackagename.MyScrollView 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@color/background" >