How to programmatically set the width of the LinearLayout or ImageView or RelativeLayout?

First of all get the device screen width:

Display display = getWindowManager().getDefaultDisplay();

Point size = new Point();

try {

    display.getRealSize(size);

} catch (NoSuchMethodError err) {

    display.getSize(size);

}

int width = size.x;

int height = size.y;

now just create a LayoutParams and set it to the Text:

LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams((int)(width/3),

                    LinearLayout.LayoutParams.WRAP_CONTENT);  

mMainLinearLayout.setLayoutParams(lp);

// OR

mProfileImage.setLayoutParams(lp);

//OR

RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams((int)(width/3),

                    LinearLayout.LayoutParams.WRAP_CONTENT);  

mLoginRelativeLayout.setLayoutParams(lp);

as same for all other layouts
which is provide according to screen size of device .

How to set editText or textview or button below of other editText or textview or button in relativeLayout in XML

<?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="@drawable/button_border">

    <ImageView         

            android:id="@+id/imageView3" 

            android:layout_width="120dp"

            android:layout_height="120dp"

            android:layout_alignParentTop="true"         

            android:layout_centerHorizontal="true" 

            android:layout_marginTop="48dp" 

            app:srcCompat="@drawable/app_logo1" />

    <TextView 

        android:id="@+id/textView2" 

        android:layout_width="wrap_content" 

        android:layout_height="wrap_content" 

        android:layout_below="@+id/imageView3"         

        android:layout_centerHorizontal="true" 

        android:text="RentLey" 

        android:textSize="30sp" />

    <EditText 

       android:id="@+id/register_email"         

       android:layout_width="300dp" 

       android:layout_height="wrap_content" 

       android:layout_centerHorizontal="true"         

       android:layout_marginTop="231dp" 

       android:background="@drawable/edittext_border" 

       android:drawableLeft="@drawable/email" 

       android:ems="10" 

       android:padding="8dp" 

       android:hint="Email"         

       android:inputType="textEmailAddress" />

    <EditText 

         android:id="@+id/register_password" 

         android:layout_width="300dp" 

         android:layout_height="wrap_content" 

         android:layout_centerHorizontal="true" 

         android:background="@drawable/edittext_border"         

         android:ems="10" 

         android:padding="8dp" 

         android:layout_marginTop="8dp" 

         android:inputType="textPassword" 

         android:drawableLeft="@drawable/password"         

         android:hint="Password" 

         android:layout_below="@+id/register_email"/>

    <EditText         

         android:id="@+id/confirm_password"         

         android:layout_width="300dp"         

         android:layout_height="wrap_content"         

         android:layout_centerHorizontal="true" 

         android:background="@drawable/edittext_border"         

         android:ems="10" 

         android:padding="8dp" 

         android:layout_marginTop="8dp"         

         android:inputType="textPassword" 

         android:drawableLeft="@drawable/password" 

         android:hint="Confirm Password"         

         android:layout_below="@+id/register_password" />

    <Button 

        android:id="@+id/register_button" 

        android:layout_width="180dp" 

        android:layout_height="wrap_content" 

        android:layout_centerHorizontal="true" 

        android:background="@drawable/button" 

        android:text="@string/register" 

        android:textAllCaps="false" 

        android:layout_marginTop="8dp" 

        android:layout_below="@+id/confirm_password"/>

</RelativeLayout>

Thanks 
Help Code 
any suggestion or query comment me