How to adjust a layout in Portrait and Landscape mode

In this code:

2. android:layout_width="match_parent" 
3. android:layout_height="match_parent" 
4. app:layout_constraintBottom_toBottomOf="parent" 
5. app:layout_constraintLeft_toLeftOf="parent" 
6. app:layout_constraintRight_toRightOf="parent" 
7. app:layout_constraintTop_toTopOf="parent">  
8.  
10. android:id="@+id/tv1" 
11. android:layout_width="300dp" 
12. android:layout_height="wrap_content" 
13. android:layout_centerHorizontal="true" 
14. android:layout_marginTop="200dp" //remove 
15. android:layout_weight="0" 
16. android:hint="USERNAME" 
17. android:textAlignment="center" 
18.  
19. /> 

In edit text just remove:

1. android:layout_marginTop="200dp" 

and then in relative layout add these line of codes:

1. android:layout_height="wrap_content" 
2. app:layout_constraintHorizontal_bias="0.5" 
3. app:layout_constraintVertical_bias="0.5" 

totally, code after modification:

2. android:layout_width="wrap_content"  
3. android:layout_height="wrap_content" 
4. app:layout_constraintBottom_toBottomOf="parent"  
5. app:layout_constraintBottom_toBottomOf="parent"  
6. app:layout_constraintLeft_toLeftOf="parent"  
7. app:layout_constraintRight_toRightOf="parent"  
8. app:layout_constraintTop_toTopOf="parent" 
9. app:layout_constraintHorizontal_bias="0.5"  
10. app:layout_constraintVertical_bias="0.5" >  
11.  
13. android:id="@+id/tv1"  
14. android:layout_width="300dp"  
15. android:layout_height="wrap_content"  
16. android:layout_centerHorizontal="true"  
17. android:layout_weight="0"  
18. android:hint="USERNAME"  
19. android:textAlignment="center"  
20. /> 

So,now it will perfectly align in landscape mode also, like this:

Hope it helpes.