Develop Reference

Android Studio Constraint Layout Preview is different than phone screen

I'm trying to program an activity in android studio that will be, at least, similar in any device. In order to achieve this, I'm already using:
Constraint Layout;
Text size as sp and other sizes as dp;
Same resolution (1920x1080) in my android preview and my physical device.
But, I'm getting a different screen behavior in each screen, as you can see by the pics.
Major differences are:
Text size seems different even using "sp" unit to define it;
Phone have a line break but preview not;
Preview has a much larger blank space when compared to the phone.
What is happening? How could I prevent this behavior and design similar layouts for different phone screens?
xml file
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
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" >
<View
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/colorPrimary" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:layout_marginLeft="20dp"
android:layout_marginRight="20dp" >
<LinearLayout
android:background="#color/colorWhite"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="45dp"
android:layout_marginBottom="45dp">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:paddingLeft="30dp"
android:paddingRight="30dp">
<TextView
android:id="#+id/templatetv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView1"
android:textColor="#color/colorPrimary"
android:textStyle="bold"
android:textSize="25sp"
android:layout_marginTop="30dp" />
<TextView
android:id="#+id/textview1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Name: John Sample"
android:textSize="18sp"
android:layout_marginTop="10dp" />
<TextView
android:id="#+id/textview2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Document number: XXX.XXX.XXX-XX"
android:textSize="18sp"
android:layout_marginTop="10dp" />
<TextView
android:id="#+id/textview3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Father name: John Sample"
android:textSize="18sp"
android:layout_marginTop="10dp" />
<TextView
android:id="#+id/textview4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Mother name: Eva Sample"
android:textSize="18sp"
android:layout_marginTop="10dp" />
<TextView
android:id="#+id/textview5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Birthdate: 01/01/1901"
android:textSize="18sp"
android:layout_marginTop="10dp" />
</LinearLayout>
</ScrollView>
</LinearLayout>
</LinearLayout>
</RelativeLayout>
Android Studio Screen Preview
Phone Screen

Try to remove this part, I think that can be the margin:
android:layout_marginLeft="20dp"
android:layout_marginRight="20dp" >

You need to define different layouts for different screens. Also, if you follow material design guidelines most of the problems will not arise. checkout the google material design documentation.

How to make a relative Layout app responsive without too many code changes?

I have an app in relative layout, inside there is:
1) A vertical linear layout having a switch and 2 editText.
2) A horizontal linear layout below the vertical one with 2 buttons.
It is working fine on a galaxy A8 phone but the horizontal linear layout is overlapping on bottom editText on smaller screen phone.
I need some guidance on how to make it responsive without too much code changes as my interface design technique is pretty poor.
Thanks for your help.
I tried to convert it to Constraint-Layout but it makes my user interface worse. The app stopped responding from it.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
android:orientation="vertical"
tools:context=".MainActivity"
android:animateLayoutChanges="true"
android:clipChildren="false">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="15dp">
<Switch
android:id="#+id/switch1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:text="French to English"
android:textSize="18sp"
android:checked="true"
android:thumbTint="#color/colorPrimary"
android:trackTint="#color/colorAccent" />
<EditText
android:id="#+id/pname"
android:layout_width="match_parent"
android:layout_height="225dp"
android:layout_marginTop="15dp"
android:maxLength="100"
android:background="#drawable/rounded_border_edittext"
android:ems="15"
android:gravity="top"
android:hint="Enter your text to translate here..."
android:inputType="textMultiLine"
android:padding="10dp" />
<EditText
android:id="#+id/target"
android:layout_width="match_parent"
android:layout_height="225dp"
android:layout_marginTop="30dp"
android:maxLength="100"
android:background="#drawable/rounded_border_edittext1"
android:ems="15"
android:gravity="top"
android:hint="Your translated text will appear here..."
android:inputType="textMultiLine"
android:padding="10dp" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentBottom="true"
android:orientation="horizontal"
android:padding="15dp">
<Button
android:id="#+id/btnsave"
style="#style/Widget.AppCompat.Button.Colored"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Save" />
<Button
android:id="#+id/btntranslate"
style="#style/Widget.AppCompat.Button.Colored"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Translate" />
</LinearLayout>
</RelativeLayout>

try setting the height to 190dp for both EditTexts in the vertical LinearLayout
android:layout_height="190dp"
and also their margingTop value to 15dp
android:layout_marginTop="15dp"
which will fit the minimum screen size of an Android device which is 426x320

Apps not looking same when i run them in actual device

I am new to android programming but I know how everything works, recently I was trying to create an app just like uber after I finished creating the launch activity i tested it on my actual device just to check whether everything looks fine but when I launched it on my device everything (layouts, imageViews, Textviews..etc) were misplaced, I have never had this problem before its just this time. could anyone please tell me where am I going wrong?
I am attaching screenshots below.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
android:background="#ffffff"
tools:context="com.example.keyur.uber.MainActivity">
<LinearLayout
android:id="#+id/layout2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/layout1"
android:orientation="horizontal">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/showtext"
android:layout_width="300dp"
android:layout_height="50dp"
android:layout_marginLeft="30dp"
android:layout_marginTop="20dp"
android:background="#ffffff"
android:fontFamily="monospace"
android:text="#string/get_moving_with_uber"
android:textColor="#000000"
android:textSize="20sp"
android:typeface="monospace" />
<ImageView
android:layout_width="40dp"
android:id="#+id/imgv"
android:layout_height="30dp"
android:layout_below="#id/showtext"
android:layout_marginLeft="30dp"
android:background="#drawable/india"
/>
<TextView
android:layout_width="40dp"
android:id="#+id/countrycode"
android:layout_height="30dp"
android:layout_centerVertical="true"
android:layout_marginStart="13dp"
android:layout_toEndOf="#+id/imgv"
android:text="#string/_91"
android:textColor="#000000"
android:textSize="22sp"
android:fontFamily="monospace"
/>
<EditText
android:id="#+id/editText"
android:layout_width="250dp"
android:layout_height="40dp"
android:layout_alignParentEnd="true"
android:layout_centerVertical="true"
android:background="#ffffff"
android:fontFamily="monospace"
android:hint="#string/enter_your_mobile_number"
android:textColor="#000000"
android:textColorHint="#484848"
android:textSize="17sp"
android:inputType="number"
/>
</RelativeLayout>
</LinearLayout>
<LinearLayout
android:id="#+id/layout1"
android:layout_width="match_parent"
android:layout_height="400dp"
android:orientation="vertical">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/imgone"
android:layout_width="match_parent"
android:layout_height="300dp"
android:background="#drawable/layoutbg" />
</RelativeLayout>
</LinearLayout>
screenshots-
this is what the app looks on pixel 4 as it is set on default.
enter image description here
this is what it looks when I switch it to pixel xl, everything gets messed up
enter image description here

Due do you are fixing the layout hight an width so each and very device have different screen size. You should use match_parent and wrap_content. If you want to split all device space in the same manner, you have to use weight.
How to use weight reference

Either you can go for "Weight Sum", or you should set your
TextView for country-code "layout_toRightOf" to image view
instead of "layout_toEndOf".

improper display of an app on nexus 5 marshmallow devices

i got a very weird type of problem while developing a basic android app.
While I've created an app in which the background image of an app is visible to all the devices except nexus devices of android marshmallow. Kindly help me in solving the error.
Below is the code and screenshot attached.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/abst"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="project.scytech.mi_agenda.LoginActivity">
<include
android:id="#+id/linearLayout"
layout="#layout/appname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/loginLayout"
android:layout_centerHorizontal="true"
android:orientation="horizontal" />
<LinearLayout
android:id="#+id/loginLayout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:orientation="vertical"
android:paddingTop="16dp">
<EditText
android:id="#+id/editTextDomainName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="#string/domainName"
android:inputType="textUri"
android:textColorHint="#FFF8E5" />
<EditText
android:id="#+id/editTextUsername"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="#string/username"
android:textColorHint="#FFF8E5" />
<EditText
android:id="#+id/editTextPassword"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:fontFamily="#string/username"
android:hint="#string/password"
android:inputType="textPassword"
android:textColorHint="#FFF8E5" />
<Button
android:id="#+id/buttonLogin"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|center"
android:layout_marginTop="16dp"
android:clickable="true"
android:onClick="loginClicked"
android:text="#string/login" />
</LinearLayout>
</RelativeLayout>

Please try to use an ImageView and set it as background.
It means:
Use a RelativeLayout or a FrameLayout and define your ImageView as the
first child. The first objects defined are the lowest in the z-order
(i.e. they will be "below" the other views).
From: Setting an ImageView to the background Android
To fit it to whole screen device use match_parent or android:scaleType="fitXY"
Your code should look like this:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:background="#000000" >
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="42dp"
tools:ignore="ContentDescription" />
//Rest of widgets......
Check also: How to make image fill RelativeLayout background without stretching
It should work

LinearLayout not resizing ImageViews correctly

As part of the on-boarding for my app, I have a series of translucent overlays that highlight the UI. Each one is a LinearLayout, initially invisible (actually "gone"), that I make visible in turn. I am having a very tough time getting one of these to display correctly on both tablets and phones, in both portrait and landscape. I can tune it to work on the phone, but then it doesn't display well on tablet-portrait.
The images here are set up to work well on 10" tablets in portrait, and they work for 7" tablets and phones in portrait, but not in landscape. In the images below, I would like the arrows (two ImageViews) to resize as needed to make room for the text. However, the Layout seems to give priority to the ImageViews no matter what I do.
(Note that I do realize I could make this work, in a way, with a RelativeLayout, however, I cannot get the translucent backgrounds to work, filling the screen, using a RelativeLayout, as far as I know.)
My question in brief: Is there a way to make LinearLayout prioritize the TextViews, giving them enough space, and resizing the ImageViews to fit the rest?
Here is a good layout (10" tablet, portrait, shown at reduced scale):
Here is a bad one with some of the text cut off (10" tablet, landscape, reduced scale):
Here is another bad one (phone):
I don't have a screenshot of the other tuning, but it displayed big arrows and no central "Tap to Continue" button.
Here is my current XML:
<RelativeLayout
android:id="#+id/main_holder"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="#+id/intro3"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical"
android:visibility="gone"
android:onClick="introClicked"
android:clickable="true">
<LinearLayout
android:id="#+id/intro3_top"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:layout_gravity="top|center_horizontal"
android:orientation="vertical"
android:gravity="top|center_horizontal">
<TextView
android:id="#+id/textViewIntro3_1"
fontPath="fonts/AsCuteAs...Heavy.ttf"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Swipe up to mark a spark completed."
android:layout_gravity="center_horizontal|top"
android:gravity="center"
android:layout_weight="1"
android:paddingBottom="5dp"
android:background="#C5000000"
android:textColor="#fff6c3"
android:textSize="30sp"/>
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal|bottom"
android:adjustViewBounds="false"
android:background="#drawable/grad_bottom"
android:padding="10dp"
android:layout_weight="1"
android:scaleType="fitCenter"
android:src="#drawable/arrow_up"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="100dp"
android:orientation="vertical"
android:layout_weight="0"
android:background="#85000000"
android:gravity="center">
<TextView
android:id="#+id/button_intro3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:alpha="0"
android:background="#drawable/roundrect"
android:onClick="introClicked"
android:padding="10dp"
android:text="Tap to Continue"
android:clickable="true"
android:enabled="true"
android:textColor="#FFFFF6C3"
android:textSize="24sp"/>
</LinearLayout>
<LinearLayout
android:id="#+id/intro3_bottom"
android:layout_width="match_parent"
android:layout_height="0dp"
android:orientation="vertical"
android:layout_weight="1"
android:layout_gravity="bottom|center_horizontal"
android:gravity="bottom|center_horizontal">
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal|bottom"
android:adjustViewBounds="false"
android:background="#drawable/grad_top"
android:layout_weight="1"
android:padding="10dp"
android:scaleType="fitCenter"
android:src="#drawable/arrow_down"/>
<TextView
android:id="#+id/textViewIntro3_2"
fontPath="fonts/AsCuteAs...Heavy.ttf"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Swipe down to reject.\n "
android:layout_gravity="center_horizontal|bottom"
android:gravity="center"
android:layout_weight="1"
android:paddingBottom="0dp"
android:background="#C5000000"
android:textColor="#fff6c3"
android:textSize="30sp"/>
</LinearLayout>
</LinearLayout>
</RelativeLayout>

There're several possible way of doing it. I've updated your layout a bit, so now it should meet your expectations:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
android:id="#+id/main_holder"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:id="#+id/intro3"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone"
android:onClick="introClicked"
android:clickable="true">
<TextView
android:id="#+id/textViewIntro3_1"
fontPath="fonts/AsCuteAs...Heavy.ttf"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Swipe up to mark a spark completed."
android:gravity="center"
android:layout_alignParentTop="true"
android:paddingBottom="5dp"
android:background="#C5000000"
android:textColor="#fff6c3"
android:textSize="30sp"/>
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="#+id/button_intro3"
android:layout_below="#+id/textViewIntro3_1"
android:adjustViewBounds="false"
android:background="#drawable/grad_bottom"
android:padding="10dp"
android:scaleType="fitCenter"
android:src="#drawable/arrow_up"/>
<TextView
android:id="#+id/button_intro3"
android:layout_centerInParent="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:alpha="0"
android:background="#drawable/roundrect"
android:onClick="introClicked"
android:padding="10dp"
android:text="Tap to Continue"
android:clickable="true"
android:enabled="true"
android:textColor="#FFFFF6C3"
android:textSize="24sp"/>
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="false"
android:background="#drawable/grad_top"
android:layout_below="#+id/button_intro3"
android:layout_above="#+id/textViewIntro3_2"
android:padding="10dp"
android:scaleType="fitCenter"
android:src="#drawable/arrow_down"/>
<TextView
android:id="#+id/textViewIntro3_2"
fontPath="fonts/AsCuteAs...Heavy.ttf"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Swipe down to reject.\n "
android:gravity="center"
android:layout_alignParentBottom="true"
android:paddingBottom="0dp"
android:background="#C5000000"
android:textColor="#fff6c3"
android:textSize="30sp"/>
</RelativeLayout>
</RelativeLayout>
What I did here is to rewrite the layout with RelativeLayout instead of LinearLayouts. It suits better here, in my humble opinion.
I hope, it helps.