ConstraintLayout Problems using

Question

I am trying to figure out why this does not work. I am adding nothing but two <include> sections in a ConstraintLayout and the layout is not following any of the constraints that I set up. I am trying to begin migrating to the use of ConstraintLayout as my go-to layout, but things like this keep pushing me back to RelativeLayout and LinearLayout.

Here is the top level layout file (the ConstraintLayout), showing some of the constraints that are not working:

<?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="match_parent"
    android:layout_height="match_parent"
    tools:layout_editor_absoluteY="81dp"
    tools:layout_editor_absoluteX="0dp">

    <include
        android:id="@+id/includeButton"
        layout="@layout/include_button_panel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintRight_toRightOf="parent" />

    <include
        android:id="@+id/includeText"
        layout="@layout/include_text_panel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent" />

</android.support.constraint.ConstraintLayout

Here is the first included layout (include_button_panel):

<?xml version="1.0" encoding="utf-8"?>
<merge
    xmlns:android="http://schemas.android.com/apk/res/android">

    <Button
        android:id="@+id/include_button_panel_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Touch me!" />

</merge>

Here is the second included layout (include_text_panel):

<?xml version="1.0" encoding="utf-8"?>
<merge
    xmlns:android="http://schemas.android.com/apk/res/android">

    <TextView
        android:id="@+id/include_text_panel_text"
        android:layout_width="wrap_content"
        android:background="#7986cb"
        android:layout_height="wrap_content"
        android:text="This is the text panel"
        android:textColor="@android:color/black"
        android:textSize="18sp" />
</merge>

score 20 · Accepted Answer · answered Sep 19 '17 at 05:08

20

Remove the <merge> tag from both of your included layouts.

When you specifiy attributes on an <include> tag, the system will apply those attributes to the root view of the included layout. The <merge> tag is a special element to allow you to have multiple views in your layout without having a root view. So all of your constraints get thrown out when your included layout uses the <merge> tag. Luckily, both of your included layouts only have one view inside the merge, so you can just remove the merge altogether.

answered Sep 19 '17 at 05:08

Ben P.

52,661
6
95
123

3

What do you do when you don't use merge tags but the `` layout still ignores constraints in its parent? I'm having this exact problem. – Cody Jan 11 '19 at 21:32
18

For anyone wondering, the answer to my problem was that I didn't include `android:layout_width` & `android:layout_height` in my `` declaration in the parent layout. https://stackoverflow.com/questions/43625651/android-add-other-layout-in-constraintlayout-using-include-tag/43656852 – Cody Jan 11 '19 at 21:46

AskNilesh · Answer 2 · 2018-05-04T04:00:31.507

try this Remove the <merge> tag from both of your included layouts

<?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="match_parent"
    android:layout_height="match_parent"
    tools:layout_editor_absoluteY="81dp"
    tools:layout_editor_absoluteX="0dp">

    <include
        android:id="@+id/includeButton"
        layout="@layout/include_button_panel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <include
        android:id="@+id/includeText"
        layout="@layout/include_text_panel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

</android.support.constraint.ConstraintLayout>

Nabzi · Answer 3 · 2020-08-22T08:18:58.860

3

As Cody mentioned in comments , the problem may be that you are not setting layout_width and layout_height for your included layout , witch doesn't produce any editor errors , but constraints don't work any more.

edited Aug 22 '20 at 08:18

answered Aug 22 '20 at 08:06

Nabzi

1,823
1
16
26

ConstraintLayout Problems using

3 Answers3