Hello im trying to put a TextView in my app, but when i drag it this happens. Ive added the style and layout xmls

Please forgive me if there is any newbie errors, im kinda new to this

My theme.xml file:

<resources xmlns:tools="http://schemas.android.com/tools">
    <!-- Base application theme. -->

    <style name="AppTheme" parent="@style/Theme.AppCompat.DayNight.NoActionBar" />

    <style name="AppBgTheme" parent="@style/AppTheme">
        <item name="android:windowBackground">@drawable/launcher_bg</item>
        <item name="android:statusBarColor">@android:color/transparent</item>
        <item name="android:navigationBarColor">@android:color/transparent</item>
        <item name="android:fontFamily">sans-serif-medium</item>
    </style>

    <style name="RobotoTextViewStyle" parent="@android:style/Widget.TextView">
        <item name="android:fontFamily">sans-serif-light</item>
    </style>

    <style name="Platform.ThemeOverlay.AppCompat.Dark" parent="@style/Platform.ThemeOverlay.AppCompat" />
    <style name="Platform.ThemeOverlay.AppCompat.Light" parent="@style/Platform.ThemeOverlay.AppCompat" />
</resources>

layout xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:tools="http://schemas.android.com/tools"
    android:layout_gravity="center"
    android:id="@id/activity_main"
    android:padding="6.0dip"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">


    <TextView
        android:id="@ id/textView111"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/app_name"
        android:textColor="#00AAFF"
        android:textSize="36sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.442" />
</androidx.constraintlayout.widget.ConstraintLayout>

CodePudding user response：

added a next to id in @id/activity_main which indicates that this id isn't identified yet and it's the first time to mention.

<?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_gravity="center"
    android:id="@ id/activity_main"
    android:padding="6.0dip"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
   >


    <TextView
        android:id="@ id/textView111"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/app_name"
        android:textColor="#00AAFF"
        android:textSize="36sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.442" />
</androidx.constraintlayout.widget.ConstraintLayout>

if that doesn't solve your problem, check your build.gradle(Module:app) may be you didn't add the androidx constraint layout dependency and that's why your layout doesn't recognize it.

dependencies {
...
    implementation 'androidx.constraintlayout:constraintlayout:2.1.0'
...
}