android - 为什么我的 NestedScrollView 不将自身定位在我的 ConstraintView 下方，尽管我使用了约束？

Question

谁能帮我？

我想在 ConstraintLayout 下面放置一个 NestedScrollView。这两个布局都在相同的层次结构级别，在外部 ConstraintLayout 内。

层次结构如下：

ConstraintLayout(1) 包含 ConstraintLayout(1.1) 和 NestedScrollView。

NestedScrollView 包含 ConstraintLayout(1.2)。

ConstraintLayout(1.2) 包含 ConstraintLayout(1.2.1) 和 ConstraintLayout(1.2.2)。

我的目标是将 NestedScrollView（包括里面的所有内容）放在 ConstraintLayout(1.1) 下方。

我试图使用约束来对齐它。但是，它不能按预期工作，我不清楚为什么 NestedScrollView 没有在内部 ConstraintLayout 下方对齐。

---

布局相关代码：

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

<!-- +++++ OPENING BRACKET OF ConstraintLayout 1 +++++-->
<androidx.constraintlayout.widget.ConstraintLayout

    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"
    android:background="@color/colorwh">

    <!-- +++++ OPENING BRACKET OF ConstraintLayout 1.1 +++++-->
    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/paymentDescriptor"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        app:layout_constraintTop_toTopOf="parent">

    </androidx.constraintlayout.widget.ConstraintLayout>
    <!-- +++++ CLOSING BRACKET OF ConstraintLayout 1.1 +++++-->

    <androidx.core.widget.NestedScrollView
        android:id="@+id/paymentRollover"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="10dp"
        android:layout_marginBottom="10dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@id/paymentDescriptor"
        android:fillViewport="true">

        <!-- +++++ OPENING BRACKET OF ConstraintLayout 1.2 +++++-->
        <androidx.constraintlayout.widget.ConstraintLayout
            android:id="@+id/availablePayments"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintBottom_toBottomOf="parent">

            <!-- +++++ OPENING BRACKET OF ConstraintLayout 1.2.1 +++++-->
            <androidx.constraintlayout.widget.ConstraintLayout
                android:id="@+id/buy_all"
                android:layout_width="match_parent"
                android:layout_height="@dimen/paymentMenuHeight"
                android:layout_marginStart="@dimen/paymentMarginLeft"
                android:layout_marginLeft="@dimen/paymentMarginLeft"
                android:layout_marginEnd="@dimen/paymentMarginRight"
                android:layout_marginRight="@dimen/paymentMarginRight"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                android:layout_marginTop="@dimen/paymentMarginTop">

                <ImageView
                    android:id="@+id/flag_all"
                    android:layout_width="@dimen/paymentFLAG_width"
                    android:layout_height="@dimen/paymentFLAG_height"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintStart_toStartOf="parent"
                    app:layout_constraintTop_toTopOf="parent"
                    android:layout_marginTop="@dimen/paymentTV_marginsVertical"
                    android:layout_marginLeft="@dimen/paymentTV_marginLeft"
                    android:layout_marginStart="@dimen/paymentTV_marginLeft"
                    android:layout_marginBottom="@dimen/paymentTV_marginsVertical">
                </ImageView>

                <TextView
                    android:id="@+id/language_all"
                    android:layout_width="@dimen/paymentTV_width"
                    android:layout_height="@dimen/paymentTV_height"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintStart_toStartOf="parent"
                    app:layout_constraintTop_toBottomOf="@id/flag_all"
                    android:layout_marginLeft="@dimen/paymentTV_marginLeft"
                    android:layout_marginStart="@dimen/paymentTV_marginLeft"
                    android:text="@string/language_all"
                    android:textSize="@dimen/paymentTV_textSize"
                    android:gravity="center"
                    android:textAllCaps="true"
                    android:textStyle="bold">
                </TextView>

                <TextView
                    android:id="@+id/descriptionBlock_all"
                    android:layout_width="@dimen/paymentDescription_width"
                    android:layout_height="@dimen/paymentDescription_height"
                    app:layout_constraintTop_toTopOf="parent"
                    app:layout_constraintLeft_toRightOf="@id/flag_all"
                    android:layout_marginTop="@dimen/paymentDescription_marginVertical"
                    android:layout_marginLeft="@dimen/paymentTV_marginLeft"
                    android:layout_marginStart="@dimen/paymentTV_marginLeft"
                    android:text="@string/descriptionBlock_all"
                    android:textSize="@dimen/paymentDescription_textSize"
                    android:gravity="center"
                    android:textStyle="italic">
                </TextView>

            </androidx.constraintlayout.widget.ConstraintLayout>
            <!-- +++++ CLOSING BRACKET OF ConstraintLayout 1.2.1 +++++-->

            <!-- +++++ OPENING BRACKET OF ConstraintLayout 1.2.2 +++++-->
        <androidx.constraintlayout.widget.ConstraintLayout
            android:id="@+id/buy_de"
            android:layout_width="match_parent"
            android:layout_height="@dimen/paymentMenuHeight"
            android:layout_marginStart="@dimen/paymentMarginLeft"
            android:layout_marginLeft="@dimen/paymentMarginLeft"
            android:layout_marginEnd="@dimen/paymentMarginRight"
            android:layout_marginRight="@dimen/paymentMarginRight"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toBottomOf="@id/buy_all"
            android:layout_marginTop="@dimen/paymentMarginTop">

            <ImageView
                android:id="@+id/flag_de"
                android:layout_width="@dimen/paymentFLAG_width"
                android:layout_height="@dimen/paymentFLAG_height"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                android:layout_marginTop="@dimen/paymentTV_marginsVertical"
                android:layout_marginLeft="@dimen/paymentTV_marginLeft"
                android:layout_marginStart="@dimen/paymentTV_marginLeft"
                android:background="@drawable/flag_col_1">
            </ImageView>

            <TextView
                android:id="@+id/language_de"
                android:layout_width="@dimen/paymentTV_width"
                android:layout_height="@dimen/paymentTV_height"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@id/flag_de"
                android:layout_marginLeft="@dimen/paymentTV_marginLeft"
                android:layout_marginStart="@dimen/paymentTV_marginLeft"
                android:text="@string/language_de"
                android:textSize="@dimen/paymentTV_textSize"
                android:gravity="center"
                android:textAllCaps="true"
                android:textStyle="bold">
            </TextView>

            <TextView
                android:id="@+id/descriptionBlock_de"
                android:layout_width="@dimen/paymentDescription_width"
                android:layout_height="@dimen/paymentDescription_height"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintLeft_toRightOf="@id/flag_de"
                android:layout_marginTop="@dimen/paymentDescription_marginVertical"
                android:layout_marginLeft="@dimen/paymentTV_marginLeft"
                android:layout_marginStart="@dimen/paymentTV_marginLeft"
                android:text="@string/descriptionBlock_de"
                android:textSize="@dimen/paymentDescription_textSize"
                android:gravity="center"
                android:textStyle="italic">
            </TextView>

        </androidx.constraintlayout.widget.ConstraintLayout>
            <!-- +++++ CLOSING BRACKET OF ConstraintLayout 1.2.2 +++++-->

        </androidx.constraintlayout.widget.ConstraintLayout>
        <!-- +++++ CLOSING BRACKET OF ConstraintLayout 1.2 +++++-->

    </androidx.core.widget.NestedScrollView>

</androidx.constraintlayout.widget.ConstraintLayout>
    <!-- +++++ CLOSING BRACKET OF ConstraintLayout 1 +++++-->

标签： androidandroid-constraintlayout