Items are in wrong place in Android Studio emulator

Question

I'm new to android studio and this is my first app. It works correctly but having an issue with the emulator, it shows the button in the wrong place.

<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:context="com.example.dell_pc.myapplication.MainActivity">

    <EditText
        android:id="@+id/txtyear"
        android:layout_width="193dp"
        android:layout_height="60dp"
        android:ems="10"
        android:hint="Enter year of birth"
        android:inputType="number"
        tools:layout_editor_absoluteY="129dp"
        tools:layout_editor_absoluteX="96dp" />

    <Button
        android:id="@+id/butage"
        android:layout_width="115dp"
        android:layout_height="41dp"
        android:onClick="BuGetAge"
        android:text="Show Age"
        tools:layout_editor_absoluteY="277dp"
        tools:layout_editor_absoluteX="135dp" />

</android.support.constraint.ConstraintLayout>

How can I make it to appear in the right place?

Solution 1

Do you absolutely need to use constraint layout? If not, you can use a relative layout, and use layout_centerHorizontal and layout_centerVertical like this:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">

    <EditText
        android:id="@+id/edittext"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:hint="blah blah"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="press"
        android:layout_centerHorizontal="true"
        android:layout_below="@id/edittext"
        />

</RelativeLayout>

Solution 2

Select Component/Item(such as BUTTON) in activity_main.xml -> click on "Infer Constrains(as I show in attached file)"

Your item will take right place in ASE

Do same for the rest Component/Items