My app layout is different from activity_main layout design

Question

I'm trying to make a imperial to metric conversion app, which is going fine, until I ran into problems with the Android Emulator. The layout is totally screwed up in the Emulator, and I have no idea why. https://i.stack.imgur.com/ygiLK.jpg

EDIT:

The whole activity_main.xml code:

<?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"
    tools:context="com.example.daniel.converter.MainActivity"
    tools:layout_editor_absoluteY="73dp"
    tools:layout_editor_absoluteX="0dp">

    <TextView
        android:id="@+id/textViewMPH"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="MPH"
        tools:layout_editor_absoluteX="55dp"
        tools:layout_editor_absoluteY="90dp" />

    <EditText
        android:id="@+id/editTextMPH"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:inputType="number"
        tools:layout_editor_absoluteX="85dp"
        tools:layout_editor_absoluteY="77dp" />

    <TextView
        android:id="@+id/textViewTO"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="To"
        tools:layout_editor_absoluteX="55dp"
        tools:layout_editor_absoluteY="132dp" />

    <TextView
        android:id="@+id/textViewKMH"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="KMH"
        tools:layout_editor_absoluteX="55dp"
        tools:layout_editor_absoluteY="168dp" />

    <EditText
        android:id="@+id/editTextKMH"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:inputType="number"
        tools:layout_editor_absoluteX="85dp"
        tools:layout_editor_absoluteY="156dp" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Convert!"
        tools:layout_editor_absoluteX="146dp"
        tools:layout_editor_absoluteY="229dp" />

</android.support.constraint.ConstraintLayout>

Answer 1

Issue is happening because you are using constraint layout but you have not provided any constraints for your items. Thus, every item is shown at (0,0) position.

Contraint Layout description:

The layout editor allows you to place widgets anywhere on the canvas, and it records the current position with designtime attributes (such as layout_editor_absoluteX.) These attributes are not applied at runtime, so if you push your layout on a device, the widgets may appear in a different location than shown in the editor. To fix this, make sure a widget has both horizontal and vertical constraints by dragging from the edge connections.

So either assign x and y values or use LinearLayout/RelativeLayout.