Unknown attribute android:layout_width, layout_height, id, gravity, layout_gravity and other attribute in xml

Question

Getting Unknown attribute error on all android tag.
In layout XML, Auto suggestion is not showing all attributes (like layout_width, layout_height, orientation, orientation & all others android attributes.)

here Things i have done to resolve this issue:

Clean Build & Rebuild

Deleted .idea

file Invalidated Caches/Restart..

option Turn On Power Save Mode.

SDk is up to date.

my xml layout:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    tools:context=".MainActivity"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_height="match_parent"
    android:layout_width="match_parent">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Hello World!"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

give us some more context. What layout/element are you using etc. Not all support all of these attrs — Tim, Nov 20 '18 at 12:53
Hi tnx for response.i am using Constraint Layout and my xml can't recognize any attribute. — Benjamin Sadeghi, Nov 20 '18 at 12:54
Do you have android namespace declared in your xml ?`xmlns:android="http://schemas.android.com/apk/res/android"` — Krzysztof Kubicki, Nov 20 '18 at 12:54
Can you share your Xml code of layout maybe there is issue in namespace — Intsab Haider, Nov 20 '18 at 12:55

score 1 · Accepted Answer · edited Nov 20 '18 at 14:41

1

I had same problem just like you and I did all of things that you've done and here is my solution. maybe problem is your targetSDKversion in gradle. if it is 28.0.0 you can change it to 27.1.1 and sync your project with gradle files.

this can help you to solve it.

edited Nov 20 '18 at 14:41

Alireza Noorali

3,129
2
33
80

answered Nov 20 '18 at 13:05

Arman Abdolmohammadi

49
3

1

downgrading targetSdk is really not a solution – Tim Nov 20 '18 at 13:06
@TimCastelijns hi yeah it is not really solution but it solved my problem. – Benjamin Sadeghi Nov 20 '18 at 13:09
@Benjamin well good luck fixing it again when you raise the targetSdk back to 28 – Tim Nov 20 '18 at 13:10
@TimCastelijns i know it is not a reliable solution but it can help in diagnosing problem so far we know that i have this problem in 28.0.0 not in other versions – Benjamin Sadeghi Nov 20 '18 at 13:13

score 0 · Answer 2 · edited Nov 20 '18 at 13:36

0

Change something in your app module build.gradle file, for example, comment a line, then click File and then Sync Project with Gradle Files.

edited Nov 20 '18 at 13:36

Alireza Noorali

3,129
2
33
80

answered Nov 20 '18 at 13:07

navylover

12,383
5
28
41

Unknown attribute android:layout_width, layout_height, id, gravity, layout_gravity and other attribute in xml

2 Answers2