Error with ConstraintLayout: No resource found that matches the given name

Question

I learn how to use ConstraintLayout. And have problem.

My activity_test.xml

Answer 1

Just replace (@id/btnScanQRCode and @id/tvReservedContInfo) with (@+id/btnScanQRCode and @+id/tvReservedContInfo).

Try this:

<?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"
    android:padding="@dimen/default_padding">

    <RelativeLayout
        android:id="@+id/reserved_layout_search"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="@+id/btnScanQRCode"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toLeftOf="@+id/btnScanQRCode"
        app:layout_constraintTop_toTopOf="parent">

        <EditText
            android:id="@+id/etSearchWorker"
            style="@style/EditTextSearch"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            />

        <Button
            android:id="@+id/btnClearSearch"
            android:layout_width="32dp"
            android:layout_height="32dp"
            android:layout_alignParentEnd="true"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:background="@drawable/ic_clear"/>

    </RelativeLayout>

    <Button
        android:id="@+id/btnScanQRCode"
        android:layout_width="@dimen/search_qr_button_size"
        android:layout_height="@dimen/search_qr_button_size"
        android:background="@drawable/button_qr_background"
        android:text="@string/button_qr_text"
        android:textColor="@color/white"
        app:layout_constraintLeft_toRightOf="@+id/reserved_layout_search"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <TextView
        android:id="@+id/tvPlanningCountInfo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:text="ddsadsas"
        app:layout_constraintHorizontal_chainStyle="spread"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toLeftOf="@+id/tvReservedContInfo"
        app:layout_constraintTop_toBottomOf="@+id/btnScanQRCode"
        />

    <TextView
        android:id="@+id/tvReservedContInfo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="dsdsadasdasad :44"
        app:layout_constraintLeft_toRightOf="@id/tvPlanningCountInfo"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="@id/tvPlanningCountInfo"
        />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/rvReserved"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginTop="@dimen/default_padding"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@id/tvPlanningCountInfo"
        app:layout_constraintBottom_toBottomOf="parent"
        />

</android.support.constraint.ConstraintLayout>

Answer 2

You are trying to set a constraint based on a element before you define it. So to fix your problem you have two different ways:

First solution: Replace your RelativeLayout(@+id/reserved_layout_search) constrains id values by:

@id/btnScanQRCode -> @+id/btnScanQRCode
@id/btnScanQRCode -> @+id/btnScanQRCode
@id/tvReservedContInfo -> @+id/tvReservedContInfo

Second solution: Declare your btnScanQRCode, btnScanQRCode and tvReservedContInfo widgets before your RelativeLayout on the XML file.