ViewPager 未显示在 NestedScrollView 内部，其中包含 ViewPager 下面的 RecyclerView

Question

我有一个 NestedScrollView，它包含一个 ConstaintLayout，里面有一个 Viewpager 和一个 Recyclerview 我的问题是 ViewPager 不显示，除非它有固定的高度，match_parent 和 wrap_content 不工作

我尝试将其高度设置为 wrap_content 并测量它为最高 child 的高度但仍然没有用，我一直在更改 fillViewport 值和其他视图'高度，将 parent 布局从 ConstaintLayout 更改为 LinearLayout 并使其 layout_weight="1" 但仍然唯一有效的是将其高度设置为固定高度

我的布局：


<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/coordinatorlayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorWhite"
    >

    <android.support.design.widget.AppBarLayout
        android:id="@+id/apSelectedLine"
        android:layout_width="match_parent"
        android:layout_height="350dp"
        android:background="@color/colorWhite">


        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/collapsing_container"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:minHeight="250dp"
            app:layout_scrollFlags="scroll|exitUntilCollapsed">


                <fragment  xmlns:android="http://schemas.android.com/apk/res/android"
                    android:id="@+id/map"
                    android:name="com.google.android.gms.maps.SupportMapFragment"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    app:layout_collapseMode="parallax" />

                <android.support.v7.widget.CardView
                    android:id="@+id/cvStep2Loading"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:layout_margin="0dp"
                    android:background="@color/colorWhite"
                    android:backgroundTint="@color/colorWhite"
                    android:minWidth="100dp"
                    android:minHeight="40dp"
                    android:visibility="gone"
                    app:cardBackgroundColor="@color/colorWhite"
                    app:cardCornerRadius="8dp"
                    app:cardElevation="16dp">

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

                        <ProgressBar
                            android:id="@+id/pbStep2Loading"
                            style="?android:attr/progressBarStyleHorizontal"
                            android:layout_width="32dp"
                            android:layout_height="32dp"
                            android:layout_marginStart="8dp"
                            android:layout_marginLeft="8dp"
                            android:layout_marginTop="8dp"
                            android:layout_marginEnd="8dp"
                            android:layout_marginRight="8dp"
                            android:layout_marginBottom="8dp"
                            android:background="@drawable/circle_shape"
                            android:indeterminate="false"
                            android:max="100"
                            android:padding="4dp"
                            android:progress="0"
                            android:progressDrawable="@drawable/circular_progress" />

                        <TextView
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            android:layout_gravity="center"
                            android:layout_marginStart="8dp"
                            android:layout_marginLeft="8dp"
                            android:layout_marginTop="8dp"
                            android:layout_marginEnd="8dp"
                            android:layout_marginRight="8dp"
                            android:layout_marginBottom="8dp"
                            android:gravity="center"
                            android:text="loading.."
                            android:textColor="@color/grey" />

                    </LinearLayout>
                </android.support.v7.widget.CardView>
        </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"
        android:id="@+id/nsBusesAndStops"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/colorWhite"
        android:fillViewport="false"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/llNestSelectedLine"
            android:visibility="visible">

            <me.relex.circleindicator.CircleIndicator
                android:id="@+id/indicator"
                android:layout_width="match_parent"
                android:layout_height="8dp"
                android:layout_marginTop="8dp"
                android:layout_marginBottom="8dp"
                android:background="@color/colorWhite"
                android:backgroundTint="@color/colorWhite"
                app:ci_drawable_unselected="@drawable/unselected_grey_circle"
                app:ci_drawable="@drawable/selected_black_circle"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintStart_toStartOf="parent"/>

            <android.support.v4.view.ViewPager
                android:id="@+id/vpSelectedLine"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@color/colorWhite"
                app:layout_constraintTop_toBottomOf="@id/indicator"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintBottom_toTopOf="@id/rvStops"
                >
            </android.support.v4.view.ViewPager>

            <android.support.v7.widget.RecyclerView
                android:id="@+id/rvStops"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:background="@color/colorWhite"
                android:backgroundTint="@color/colorWhite"
                android:nestedScrollingEnabled="false"
                app:layout_constraintTop_toBottomOf="@id/vpSelectedLine"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintBottom_toBottomOf="parent"
                />

        </android.support.constraint.ConstraintLayout>


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



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

我不能让它固定高度，因为 Viewpager 包含一个动态的 RecyclerView...那么如何在不固定 ViewPager 高度的情况下解决这个问题？

Answer 1

尝试将 ViewPager 和 RecyclerView 放在 FitWindowsFrameLayout 和 layout_height="wrap_content" 中，这样你的代码看起来像这样

<android.support.design.widget.CoordinatorLayout
...
 <android.support.v4.widget.NestedScrollView
            xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:app="http://schemas.android.com/apk/res-auto"
            android:id="@+id/nsBusesAndStops"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/colorWhite"
            android:fillViewport="false"
            app:layout_behavior="@string/appbar_scrolling_view_behavior">

        <android.support.constraint.ConstraintLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:id="@+id/llNestSelectedLine"
                android:visibility="visible">

            <me.relex.circleindicator.CircleIndicator
                    android:id="@+id/indicator"
                    android:layout_width="match_parent"
                    android:layout_height="8dp"
                    android:layout_marginTop="8dp"
                    android:layout_marginBottom="8dp"
                    android:background="@color/colorWhite"
                    android:backgroundTint="@color/colorWhite"
                    app:ci_drawable_unselected="@drawable/unselected_grey_circle"
                    app:ci_drawable="@drawable/selected_black_circle"
                    app:layout_constraintTop_toTopOf="parent"
                    app:layout_constraintRight_toRightOf="parent"
                    app:layout_constraintEnd_toEndOf="parent"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintStart_toStartOf="parent"/>

            <android.support.v7.widget.FitWindowsFrameLayout
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    tools:ignore="MissingConstraints">
                <android.support.v4.view.ViewPager
                        android:id="@+id/vpSelectedLine"
                        android:layout_width="match_parent"
                        android:layout_height="match_parent"
                        android:background="@color/colorWhite"
                        app:layout_constraintTop_toBottomOf="@id/indicator"
                        app:layout_constraintRight_toRightOf="parent"
                        app:layout_constraintEnd_toEndOf="parent"
                        app:layout_constraintLeft_toLeftOf="parent"
                        app:layout_constraintStart_toStartOf="parent"
                        app:layout_constraintBottom_toTopOf="@id/rvStops"
                >
                </android.support.v4.view.ViewPager>

                <android.support.v7.widget.RecyclerView
                        android:id="@+id/rvStops"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:background="@color/colorWhite"
                        android:backgroundTint="@color/colorWhite"
                        android:nestedScrollingEnabled="false"
                        app:layout_constraintTop_toBottomOf="@id/vpSelectedLine"
                        app:layout_constraintRight_toRightOf="parent"
                        app:layout_constraintEnd_toEndOf="parent"
                        app:layout_constraintLeft_toLeftOf="parent"
                        app:layout_constraintStart_toStartOf="parent"
                        app:layout_constraintBottom_toBottomOf="parent"/>

            </android.support.v7.widget.FitWindowsFrameLayout>


        </android.support.constraint.ConstraintLayout>


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



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

有关如何使用的更多信息FitWindowsFrameLayout this googlesource link

Answer 2

在尝试解决这个问题将近一天后，我自己想出了这个解决方案，我最初在 xml 中将 ViewPager 高度设置为固定高度（例如 100dp），然后当数据来自服务器时我将 ViewPager 的高度调整为儿童的总高度，请注意我在 ViewPager 中有一个 RecyclerView，这是我为此使用的 Kotlin 代码：

   fun resizeViewPager(busesList: MutableList<Bus>){

        childRecyclerView?.viewTreeObserver?.addOnGlobalLayoutListener(object : ViewTreeObserver.OnGlobalLayoutListener{
            override fun onGlobalLayout() {
                val firstChild = childRecyclerView?.getChildAt(0)
                val height = firstChild?.height
                if (height != null){
                    val totalHeight = height * busesList.size
                    val layoutParams = viewPager.layoutParams

                    layoutParams.height = totalHeight

                    viewPager.layoutParams = layoutParams
                    viewPager.requestLayout()
                }

                childRecyclerView?.viewTreeObserver?.removeOnGlobalLayoutListener(this)
            }
        })


    }

谁能解释一下为什么会出现这个问题？有更好的解决方案吗？

ViewPager 未显示在 NestedScrollView 内部，其中包含 ViewPager 下面的 RecyclerView

ViewPager not showing inside NestedScrollView which contains RecyclerView below ViewPager

xml

android

android-viewpager

android-recyclerview

nestedscrollview