Android的CoordinatorLayout + AppbarLayout + Viewpager总是滚动

问题描述

我有一个经典布局与顶部的工具栏，它下面的一个TabLayout，并从TabLayout一个ViewPager切换标签。当在ViewPager内容是滚动的，工具栏应该滚动的视线之外，而TabLayout应该遵循，当它到达顶部粘。

I have a classic layout with a ToolBar on the top, a TabLayout below it, and a ViewPager switching tabs from the TabLayout. When content in the ViewPager is scrollable, the ToolBar should scroll out of sight, and the TabLayout should follow and stick when it reaches the top.

这一切都是在我目前的code好，除了在工具栏始终是滚动​​的，无论ViewPager内容的大小。看到我下面code。关于如何解决此问题的任何高见？

All this is good in my current code, except, the ToolBar is always scrollable, regardless of the size of the ViewPager's content. See my code below. Any brilliant ideas on how to fix this?

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

    <android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/primary"
        android:orientation="vertical">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/AppTheme.ToolBar"
            app:layout_scrollFlags="scroll|enterAlways" />

        <android.support.design.widget.TabLayout
            android:id="@+id/tabs"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/colorPrimary"
            android:scrollbars="horizontal"
            app:tabIndicatorColor="@color/black_text" />

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

    <android.support.v4.view.ViewPager
        android:id="@+id/tabs_activity_view_pager"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

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

编辑：

我可以看到viewPager的高度相同的高度为整个根视图。这可能是intentded作为appbar_scrolling_view_behavior似乎增加一个顶部和底部偏移。然而，这似乎不可思议，因为这将导致始终滚动工具栏和TabBar。

I can see that the viewPager's height is the same as the height for the entire root view. This might be intentded, as the appbar_scrolling_view_behavior does seem to add a top and bottom offset. It does however seem weird, since it will result in always scrolling the toolbar and tabbar.

推荐答案

根据其他样品，我自己的code和（有点杂乱）来源$ C ​​$的appbar_scrolling_view_behavior的C：

Based on other samples, my own code, and the (somewhat messy) source code of the appbar_scrolling_view_behavior:

        public boolean onDependentViewChanged(CoordinatorLayout parent, View child,
            View dependency) {
        final CoordinatorLayout.Behavior behavior =
                ((CoordinatorLayout.LayoutParams) dependency.getLayoutParams()).getBehavior();
        if (behavior instanceof Behavior) {
            // Offset the child so that it is below the app-bar (with any overlap)

            final int appBarOffset = ((Behavior) behavior)
                    .getTopBottomOffsetForScrollingSibling();
            final int expandedMax = dependency.getHeight() - mOverlayTop;
            final int collapsedMin = parent.getHeight() - child.getHeight();

            if (mOverlayTop != 0 && dependency instanceof AppBarLayout) {
                // If we have an overlap top, and the dependency is an AppBarLayout, we control
                // the offset ourselves based on the appbar's scroll progress. This is so that
                // the scroll happens sequentially rather than linearly
                final int scrollRange = ((AppBarLayout) dependency).getTotalScrollRange();
                setTopAndBottomOffset(AnimationUtils.lerp(expandedMax, collapsedMin,
                        Math.abs(appBarOffset) / (float) scrollRange));
            } else {
                setTopAndBottomOffset(dependency.getHeight() - mOverlayTop + appBarOffset);
            }
        }
        return false;
    }

我读这在某种程度上解释这个问题，因为这是预期与此code行为。

I'm reading this in a way explaining the problem, as this is expected behavior with this code.

我认为我们需要写我们自己的滚动的行为，专门为RecyclerView，

I think we need to write our own scroll behavior, specially for the RecyclerView,

这篇关于Android的CoordinatorLayout + AppbarLayout + Viewpager总是滚动的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！