constraintlayout wrapcontent 直到适合屏幕

Question

我想制作recyclerview wrap_content。但我不希望“添加项目”按钮在添加项目时超出屏幕。如何解决这个问题？

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

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        app:layout_constraintBottom_toTopOf="@id/buttonAdd"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0"
        app:layout_constraintVertical_chainStyle="packed"
        tools:itemCount="16"
        tools:listitem="@layout/item_ver" />

    <com.google.android.material.button.MaterialButton
        android:id="@+id/buttonAdd"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Add Item"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/recyclerView" />

</androidx.constraintlayout.widget.ConstraintLayout>

Answer 1

您只需要在

app:layout_constrainedHeight="true"

中添加

androidx.recyclerview.widget.RecyclerView

，这样您的代码将如下所示

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

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constrainedHeight="true"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        app:layout_constraintBottom_toTopOf="@id/buttonAdd"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0"
        app:layout_constraintVertical_chainStyle="packed"
        tools:itemCount="50"
        tools:listitem="@layout/item_ver" />

    <com.google.android.material.button.MaterialButton
        android:id="@+id/buttonAdd"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Add Item"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/recyclerView" />

</androidx.constraintlayout.widget.ConstraintLayout>