Android Studio showing different design in emulator

Issue

This is what I have designed in Android Studio [Design][1]

In emulator it shows like this [Emulator][2]

Code: activity_main.xml

<?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_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:text="@string/app_name"
        app:layout_constraintHeight_percent="0.1"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintWidth_percent="0.3"
        tools:text="Happy Birthday Thirumalai"
        tools:visibility="visible" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginBottom="16dp"
        android:text="@string/family"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHeight_percent="0.1"
        app:layout_constraintWidth_percent="0.3"/>
</androidx.constraintlayout.widget.ConstraintLayout>

Code: AndroidManifest.xml

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.HappyBirthday">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

How do I solve this? Thank You !! [1]: https://i.stack.imgur.com/dQn8s.png [2]: https://i.stack.imgur.com/8hJAa.png

Solution

The issue is your NameSpaces.

To display text just to see how it would appear during design we use tools:text namespace. To show the actual text on emulator or an Android Device we use android:text.

You can also see the difference on the Design attributes.

So what you need to do is to work with android:text namespace

<TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:text="Happy Birthday Thirumalai"



        android:layout_marginLeft="16dp" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginBottom="16dp"
        android:text="@string/family"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        android:layout_marginRight="16dp" />

Answered By - Tonnie