webview 高度在nestedScrollView 内无限增长

问题描述

这是我的布局.当我加载 google.com 时，webview 的高度会无限增长.webview 的 onSizeChange 函数不断被调用，我可以看到 webview 不断扩展.我已经尝试了 22.2.1 和 23.1.0 的设计和 appcompat 库，但没有效果.

有什么解决办法吗?:-|

实际上，这是一个在该线程，并且根据这位 Google 工程师，>
这就像在桌面上一样，您将浏览器窗口的大小调整为页面的高度，因此它无法垂直滚动.滚动发生在 NestedScrollView 而不是 webview 本身.所以页面中没有js的结果是看到任何滚动事件，所以它不知道你已经滚动到页面末尾加载了更多内容.
所以，最重要的是，不要将您的 WebView 放在 NestedScrollView 中.您应该让 WebView 滚动网页本身.快乐编码！:)
This is my layout. When i load google.com, the webview's height keeps growing indefinitely. The onSizeChange function of the webview keeps getting called and i can see the webview keeps expanding indefinitely.  I've tried 22.2.1 and 23.1.0 of the design and appcompat libraries and no effect. 

Any solution ? :-|
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/black">

<android.support.v4.widget.NestedScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="fill_vertical"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <com.example.ajay.scrollabletoolbar.MyWebView
        android:id="@+id/webview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentTop="true"/>
</android.support.v4.widget.NestedScrollView>

<android.support.design.widget.AppBarLayout
    android:id="@+id/appbarlayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true">

    <android.support.v7.widget.Toolbar
        android:id="@+id/restricted_browser_toolbar"
        android:layout_width="match_parent"
        android:layout_height="?actionBarSize"
        android:background="@color/colorPrimary"
        app:layout_scrollFlags="scroll|enterAlways">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="#FFFFFF"
            android:descendantFocusability="beforeDescendants"
            android:focusableInTouchMode="true">

            <EditText
                android:id="@+id/current_url"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_centerVertical="true"
                android:backgroundTint="@android:color/darker_gray"
                android:dropDownAnchor="@+id/restricted_browser_toolbar"
                android:hint="hint hint"
                android:imeOptions="actionGo|flagNoExtractUi"
                android:inputType="textNoSuggestions|textUri"
                android:paddingBottom="8dp"
                android:paddingEnd="8dp"
                android:paddingStart="8dp"
                android:singleLine="true"/>

            <ImageView
                android:id="@+id/clear_url_text"
                android:layout_width="48dp"
                android:layout_height="48dp"
                android:layout_alignRight="@+id/current_url"
                android:layout_centerVertical="true"
                android:layout_marginRight="8dp"
                android:src="@android:drawable/ic_menu_close_clear_cancel"
                android:visibility="gone"/>
        </RelativeLayout>
    </android.support.v7.widget.Toolbar>
</android.support.design.widget.AppBarLayout>
 解决方案 
In one sentence, you just can't put your WebView inside NestedScrollView. This is working as intended.
If you put a WebView inside NestedScrollView (or ScrollView), your WebView measures its dimensions with View.MeasureSpec.UNSPECIFIED requirement. No matter you set MATCH_PARENT or even fixed size like 100dp for your WebView's height. NestedScrollView forces its children measure themselves with View.MeasureSpec.UNSPECIFIED requirement. It all happens at NestedScrollView's measureChild() method. It goes like below :
@Override
protected void measureChild(View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec) {
    ViewGroup.LayoutParams lp = child.getLayoutParams();
    int childWidthMeasureSpec;
    int childHeightMeasureSpec;
    childWidthMeasureSpec = getChildMeasureSpec(parentWidthMeasureSpec, getPaddingLeft()
            + getPaddingRight(), lp.width);
    childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
    child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
And MeasureSpec.UNSPECIFIED means, as its label implies, it can be whatever size it wants. I think this slide from the "Writing Custom Views for Android" session at Google I/O 2013 will help you to understand it.
Actually this is an issue which was discussed in this thread, and according to this Google engineer, 
So, bottom line is, DO NOT put your WebView inside NestedScrollView. You should let WebView scroll the web page itself. Happy coding! :)
                        
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