make RecyclerView's height to “wrap_content” in Constraint layout

Question

i\'m trying to set the height of recycler view on wrap_content and make it respect that,but it will exceed the other widget on layout. what can i do now?

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Answer 1

i had the same issue and i find this solution: you should add this attribute to your recyclerview and it makes your recyclerview wrap_content in the constraint_layout:

app:layout_constraintHeight_default="wrap"

let me know if this solution fixed your problem.

EDIT : recycler's height should be 0dp.

EDIT 2 : in the newer versions of support library, use this code:

android:layout_height="wrap_content"
app:layout_constrainedHeight="true"

Answer 2

I had this issue. I needed to build a UI page that contained a RecyclerView with an unknown number of elements that should scroll. The page had the the following layout:

LinearLayout
    ConstraintLayout
        TextView
        RecyclerView
        TextView

and I wanted heights to be determined procedurally for everything using match_parent and wrap_content.

I wanted the RecyclerView to use all the space available between the two TextViews.

The key was to give the RecyclerView an "impossible" constraint, by doing this:

app:layout_constraintTop_toBottomOf="@+id/topTextView"
app:layout_constraintBottom_toTopOf="@+id/bottomTextView"

and adding this:

app:layout_constrainedHeight="true"

If you need to add margin between the top TextView and RecyclerView (and/or the bottom TextView and RecyclerView) put the margin on the RecyclerView, not the TextViews.

Code Examples

Below is the actual code I'm using (with some text styling removed for readability)

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

    <android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="#1A1A1C">

        <TextView
            android:id="@+id/selectcampus_es"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="32dp"
            android:layout_marginEnd="32dp"
            android:layout_marginTop="48dp"
            android:text="Pick a campus."
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <android.support.v7.widget.RecyclerView
            android:id="@+id/recycler_view"
            android:layout_marginTop="24dp"
            android:layout_marginBottom="24dp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:layout_constrainedHeight="true"
            app:layout_constraintTop_toBottomOf="@+id/selectcampus_es"
            app:layout_constraintBottom_toTopOf="@+id/comingsoon_es" />

        <TextView
            android:id="@+id/comingsoon_es"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="32dp"
            android:layout_marginEnd="32dp"
            android:layout_marginBottom="48dp"
            android:text="More campuses coming soon."
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintBottom_toBottomOf="parent" />

    </android.support.constraint.ConstraintLayout>
</LinearLayout>

As a final note, the HolderView also uses only wrap_content. Here's that code as well:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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="wrap_content"
        android:layout_height="wrap_content">

    <android.support.v7.widget.AppCompatTextView
            android:id="@+id/name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            android:layout_marginLeft="20dp"
            android:layout_marginTop="15dp"
            android:text="Avondale"
            android:alpha="1"/>
</android.support.constraint.ConstraintLayout>

Answer 3

app:layout_constraintHeight_default="wrap"

is deprecated in newer versions of the Support library, so consider using

android:layout_height="wrap_content"
app:layout_constrainedHeight="true"

instead.