Develop Reference

Cannot align rows with chain restraints

I have a widget that, no matter what constraints I place upon it and other widgets, including the addition of barriers, always positions itself at the top of the layout.
This is a fairly simple arrangement of two rows of two elements each, not aligned column wise. The first element in each row is a TextView label, the second an input (Spinner).
There is also a lone TextView title above the first row stretching all the way across. By my understanding and previous experience with constraint layout, this shouldn't require a barrier between the rows, and that was my initial version.
This is the design view, where the selected element ("Credentials") is supposed to be in the second row but instead appears above the first row, over top of the title TextView ("PKIX"):
Actual result in the emulator looks much the same. The selected "Credentials" element is the fourth of five elements in the XML layout below. All of the other elements are in the right place.
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/addsrv_pkix_title"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:background="#drawable/bottomborder"
android:text="PKIX"
android:textAlignment="center"
android:layout_marginHorizontal="10sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toTopOf="#+id/addsrv_trust_lbl"
/>
<TextView
android:id="#+id/addsrv_trust_lbl"
android:text="Trust"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingHorizontal="10sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toStartOf="#+id/addsrv_trust_spin"
app:layout_constraintTop_toBottomOf="#+id/addsrv_pkix_title"
app:layout_constraintBaseline_toBaselineOf="#+id/addsrv_trust_spin"
app:layout_constraintBottom_toTopOf="#+id/addsrv_cred_lbl"
/>
<Spinner
android:id="#+id/addsrv_trust_spin"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintStart_toEndOf="#+id/addsrv_trust_lbl"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#+id/addsrv_pkix_title"
app:layout_constraintBottom_toTopOf="#+id/addsrv_cred_spin"
/>
<TextView
android:id="#+id/addsrv_cred_lbl"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:paddingHorizontal="10sp"
android:text="Credentials"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toStartOf="#+id/addsrv_cred_spin"
app:layout_constraintTop_toBottomOf="#+id/addsrv_trust_lbl"
app:layout_constraintBaseline_toBaselineOf="#+id/addsrv_cred_spin"
/>
<Spinner
android:id="#+id/addsrv_cred_spin"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintStart_toEndOf="#+id/addsrv_cred_lbl"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#+id/addsrv_trust_spin"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
I'm perplexed. The addsrv_cred_lbl TextView ("Credentials") is:
Start aligned with parent.
End aligned with the addsrv_cred_spin spinner, which appears correctly positioned;
this alignment is reciprocated to create a horizontal chain. They are also baseline
aligned.
Top aligned with the bottom of the TextView above it, addsrv_trust_lbl.
This alignment is also reciprocated.
There's no bottom alignment yet (there's another row to go); bottom aligning it with the parent makes no difference unless I bottom align the spinner from the same row, in which case the result goes from bad to worse.
Since this did not work, I tried to use a barrier between the rows. If I use it as a "top", with the second row widgets as the constraint referents, the barrier appears at the top, above the title, regardless of what constraints are used to position it below the first row. Used as a "bottom", with the first row widgets referenced and the second row chained below it (which is more logical), things are a little bit better in that the barrier appears in the right place -- but the "Credentials" widget is still up top.
The design view of this looks exactly the same as the previous one except the barrier is visible below the first row. In the XML, I aslo added optimizationLevel="none" after having read this can help with misbehaving barriers (but it made no difference). There's also a few stylistic elements added back here (such as font size) I removed for brevity before.
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_optimizationLevel="none"
>
<TextView
android:id="#+id/addsrv_pkix_title"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:background="#drawable/bottomborder"
android:backgroundTint="#color/tbar"
android:text="PKIX"
android:textAlignment="center"
android:textSize="#dimen/addsrv_bigfont"
android:textColor="#color/titleText"
android:layout_marginHorizontal="10sp"
app:layout_constraintBottom_toTopOf="#+id/addsrv_trust_lbl"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>
<TextView
android:id="#+id/addsrv_trust_lbl"
android:text="Trust"
android:textSize="#dimen/addsrv_fontsz"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingHorizontal="10sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toStartOf="#+id/addsrv_trust_spin"
app:layout_constraintTop_toBottomOf="#+id/addsrv_pkix_title"
app:layout_constraintBaseline_toBaselineOf="#+id/addsrv_trust_spin"
app:layout_constraintBottom_toTopOf="#+id/addsrv_bar1"
app:layout_constraintHorizontal_chainStyle="packed"
/>
<Spinner
android:id="#+id/addsrv_trust_spin"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintStart_toEndOf="#+id/addsrv_trust_lbl"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#+id/addsrv_pkix_title"
app:layout_constraintBottom_toTopOf="#+id/addsrv_bar1"
/>
<androidx.constraintlayout.widget.Barrier
android:id="#+id/addsrv_bar1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:barrierDirection="bottom"
app:constraint_referenced_ids="addsrv_trust_lbl,addsrv_trust_spin"
app:layout_constraintBottom_toTopOf="#+id/addsrv_cred_lbl"
/>
<TextView
android:id="#+id/addsrv_cred_lbl"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingHorizontal="10sp"
android:text="Credentials"
android:textSize="#dimen/addsrv_fontsz"
app:layout_constraintBaseline_toBaselineOf="#+id/addsrv_cred_spin"
app:layout_constraintEnd_toStartOf="#+id/addsrv_cred_spin"
app:layout_constraintHorizontal_chainStyle="packed"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/addsrv_bar1" />
<Spinner
android:id="#+id/addsrv_cred_spin"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintStart_toEndOf="#+id/addsrv_cred_lbl"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#+id/addsrv_bar1"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
Am I correct in observing that some of the constraints on addsrv_cred_lbl are being completely ignored? Doesn't topToBottom mean that the top of the widget is aligned with the bottom of the other? Instead, it seems simply to mean that they will be connected with a squiggly, potentially curved and convoluted line in the design view, and the spacial relation of the two widgets is arbitrary, such that the semantic logic might as well be inverted, "top = bottom, bottom = top", etc.
Please note that I do not want to use absolute values to position anything. If the only way to get this to work is to do that, constraint layout seems a complete waste of time even in this simple case, and I'd rather just stack some liner layouts.

The problem is that Spinner doesn't have a baseline. You were trying to tie it to the baseline of the item inside the Spinner is my guess - ConstraintLayout can't reach children of its children.
You can check it via the design tab with a right click. TextViews will show an option "Show baseline" but the Spinner doesn't.
Also snippet from the doc
Align the text baseline of a view to the text baseline of another
view.
That's what baselines are for, if you want two TextViews connect together so they don't have the height where the text starts messed up.
I think there is a tiny flaw in your approach to the chain. You were setting the top constraint of both elements in each row to the bottom of the previous row(or title in the first row). Even if the Spinner would have a baseline, this would make the label off-centered in relation to the Spinner(slightly higher because the baseline of a text is higher than the actual bottom of the view).
I think the best approach in these types of layouts is to have one guiding element(which is also the element of the chain) that represents the row and let other elements be positioned in relation to it.
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/addsrv_pkix_title"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="PKIX"
android:textAlignment="center"
android:layout_marginHorizontal="10sp"
app:layout_constraintVertical_chainStyle="spread"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toTopOf="#+id/addsrv_trust_spin"
/>
<TextView
android:id="#+id/addsrv_trust_lbl"
android:text="Trust"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingHorizontal="10sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toStartOf="#+id/addsrv_trust_spin"
app:layout_constraintTop_toTopOf="#+id/addsrv_trust_spin"
app:layout_constraintBottom_toBottomOf="#+id/addsrv_trust_spin"
/>
<Spinner
android:id="#+id/addsrv_trust_spin"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintStart_toEndOf="#+id/addsrv_trust_lbl"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#+id/addsrv_pkix_title"
app:layout_constraintBottom_toTopOf="#+id/addsrv_cred_spin"
/>
<TextView
android:id="#+id/addsrv_cred_lbl"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingHorizontal="10sp"
android:text="Credentials"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toStartOf="#+id/addsrv_cred_spin"
app:layout_constraintTop_toTopOf="#+id/addsrv_cred_spin"
app:layout_constraintBottom_toBottomOf="#+id/addsrv_cred_spin"
/>
<Spinner
android:id="#+id/addsrv_cred_spin"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintStart_toEndOf="#+id/addsrv_cred_lbl"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#+id/addsrv_trust_spin"
app:layout_constraintBottom_toBottomOf="parent"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
NOTE: I added the last bottom constraint to the parent and "spread" to the chain for demonstration but also know that if you don't have the bottom of the last view constrained to something - it's not a chain.

Working with ConstraintLayout is easy if you obey few simple rules:
Create one chain. That means Views hooking to each other reciprocally, all the way.
Now that you have a working chain, you can manipulate it with layout_constraintVertical_bias and layout_constraintVertical_chainStyle. If changing those does nothing, it means your chain is broken.
hook remaining Views to ones laid out by the chain
every control must have 4 constraints: top, bottom, start and end
do not create competing chains and try to force them into working together.
Spinner cannot have baseline, only TextView and its descendants have it. Spinner is AdapterView, so it can contain whatever you can imagine.
BTW: don't use #+id to refer to existing ids. Plus means creating new id, so if you make a typo it will create new id that refers to nothing instead of error "there's no such id".
Here's an example: top label and Spinners form the main chain and side labels are positioned each to their Spinner:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<TextView
android:id="#+id/addsrv_pkix_title"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginHorizontal="10sp"
android:background=""
android:text="PKIX"
android:textAlignment="center"
app:layout_constraintBottom_toTopOf="#id/addsrv_trust_spin"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0"
app:layout_constraintVertical_chainStyle="packed"
/>
<TextView
android:id="#+id/addsrv_trust_lbl"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingHorizontal="10sp"
android:text="Trust"
app:layout_constraintBottom_toBottomOf="#id/addsrv_trust_spin"
app:layout_constraintEnd_toStartOf="#id/addsrv_trust_spin"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="#id/addsrv_trust_spin"
app:layout_constraintVertical_bias="1.0"
/>
<Spinner
android:id="#+id/addsrv_trust_spin"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintBottom_toTopOf="#id/addsrv_cred_spin"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="#id/addsrv_trust_lbl"
app:layout_constraintTop_toBottomOf="#id/addsrv_pkix_title"
app:layout_constraintVertical_bias="0.0"
/>
<TextView
android:id="#+id/addsrv_cred_lbl"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingHorizontal="10sp"
android:text="Credentials"
app:layout_constraintBottom_toBottomOf="#id/addsrv_cred_spin"
app:layout_constraintEnd_toStartOf="#id/addsrv_cred_spin"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="#id/addsrv_cred_spin"
app:layout_constraintVertical_bias="1.0"
/>
<Spinner
android:id="#+id/addsrv_cred_spin"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="#id/addsrv_cred_lbl"
app:layout_constraintTop_toBottomOf="#id/addsrv_trust_spin"
/>
</androidx.constraintlayout.widget.ConstraintLayout>

Custom Layout is not being centered inside a listview using constraintLayout

I'm trying to center the items of my listview which are a custom view to the center of a constraint layout but they only show at the left side.
I tried setting the horizontal bias of both the constraint and the list view to 50 and to 100 but the listView still doesn't show the Items in the center or anywhere else other than at the start. I tried using layout_centerhorizontal="true" but that does not work either. Bare in mind that the listview is being inflated inside a fragment which is inside a ViewPager.
UPDATE:
I fixed it by wrapping the custom_item xml inside a linear layout which filled the entire screen horizontally and added horizontal center gravity to the item.
Here is my xml:
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/parentConstraint_tutor_fragment_loged"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginTop="32dp"
android:layout_marginBottom="8dp"
android:visibility="visible"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0">
<ListView
android:id="#+id/tutorListView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:divider="#null"
android:dividerHeight="0dp"
android:listSelector="#android:color/transparent"
android:overScrollMode="never"
android:scrollbars="none"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0"/>
</androidx.constraintlayout.widget.ConstraintLayout>
And here is the custom_Item:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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="323dp"
android:layout_height="68dp"
android:layout_gravity="center_horizontal"
android:background="#drawable/tutor_entry_panel_phones_selector">
<ImageView
android:id="#+id/tutorIcon_cell"
android:layout_width="35dp"
android:layout_height="33dp"
android:layout_marginStart="12dp"
android:layout_marginLeft="12dp"
android:scaleType="fitCenter"
android:tint="#color/BlueColor"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="#drawable/login_tutor_icon" />
<TextView
android:id="#+id/userLogin_nameTextV"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="4dp"
android:layout_marginLeft="4dp"
android:layout_marginEnd="22dp"
android:layout_marginRight="22dp"
android:gravity="center"
android:textColor="#color/BlueColor"
android:textSize="16sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="#+id/deleteIconPhones"
app:layout_constraintStart_toEndOf="#+id/tutorIcon_cell"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:id="#+id/deleteIconPhones"
android:layout_width="32dp"
android:layout_height="36dp"
android:layout_marginEnd="16dp"
android:layout_marginRight="16dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
I just need the custom view inside the listview to be in the center of the constraint layout. here is a Screenshot of the current state:
https://ibb.co/88KVQvq
desired state will be with the custom_item in the middle and not in the beginning of the constraintLayout:
https://ibb.co/XbtWJkw
custom_item snapshot:
https://ibb.co/rkDXmGs
Blueprint view of the viewpager in which this fragment is contained (Im trying to get the custom_item centered inside the viewpager's fragment):
https://ibb.co/XVR02Kq

If it is a custom_listView then Do change in the custom_layout.xml - (Whatever you gave the name of the layout) and check it again.

First of all, all these parameters in <ConstraintLayout ...> element are unnecessary:
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0"
They don't have any meaning. Those parameters are used on elements inside ConstraintLayout, not on Layout itself. Layout fills all available space (in case of activity, it is whole screen), whatever layout are you using. Generally, just use match_parent/wrap_content in width/height, and that's it.
Secondly, based on your screen I cannot say where the ViewPager is located. It looks like ViewPager itself is left aligned in whole activity, but I am not sure. If it is, than it is the reason why everything squashed to left side. You can activate Developer Options on your device, then find and activate option Show Layout Bounds, than you will see on your screen borders of all rendered elements and see if this is the case.
Additionally, your item does not have very proper layout. If you want to chain these three elements, all of them should have all four layout_constraintXxx_toYyyOf elements. You can find it described here. I am not sure that this is the cause of your problem, but certainly is something that might cause the issue. Also, unless you really need to use ConstraintLayout, I would advise to use here LinearLayout, or even just plain text/button with drawableStart and drawableEnd set. It is documented on TextView class (Button is just a subclass of a TextView.)

Android Constraint Layout alignemnt

Im facing an issue with ConstraintLayout.
I have a view which has 3 textviews T1, T2 and T3.
Precondition: T1,T2 is having 4dp margin top.
Problem:
T3 needs to be top should be aligned to topmost view.
Condition is T1 will be visible or gone based on certain condition.
If T1 is visible the margintop will be 8dp and when T1 is not visible T2 will have 12dp margintop.
<?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">
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:text="T1"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/textView9"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="4dp"
android:text="T2"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/textView" />
<TextView
android:id="#+id/textView10"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:text="T3"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="#+id/textView" />
</android.support.constraint.ConstraintLayout>
Is this possible by XML or I need to configure programmatically?

You can't achieve this only with XML, what you did is create a screen using constraint layout. If you want to add some logic to change the position of some view under certain conditions you will have to write it programmatically.Here is a good thread about the subject.

I don't know exactly your use case,but you can achieve this setting view to invisible instead of gone.
View.GONE This view is invisible, and it doesn't take any space for layout purposes.
View.INVISIBLE This view is invisible, but it still takes up space for layout purposes.

You can use layout_goneMarginTop to have a different margin when your view is GONE.
You can also use SequenceLayout for better flexibility on managing your layout. Use visibilityElement on each Span you want to be gone when your related view is gone.

What's happen about my ConstraintLayout why I am running?

everyone
I am a beginner. I tried to use ConstraintLayout with Android studio 3.1.1 and genymotion. when I run the project on genymotion emulator, It is different from what I have coded. Images FYI.

Each component needs to be constrained to be able to display correctly. I think you should do it. Because some TextView components seem to have no constraints

For Constrain Layout, You can to pull all point from the box of your TextView (for example)to top, bottom, left and right to remain it in the position. It could takes sometimes if have lots of button or textView or what so ever.
ConstrainLayout
sampleCode
<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">
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:text="Button"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.32" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="16dp"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:text="TextView"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
You have to pull the line from the dot of the box to everyside so it could stay at the position.
Since you are a beginner, I think You can consider LinearLayout.
As LinearLayout, it is align those textView and button or anything inside in arrangement. As long as You it in vertical or horizontal.
Example
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
....
//Edit your layout
</LinearLayout>
Another good layout for beginner is RelativeLayout
RelativeLayout you can drag and drop the textView or button or what so ever to the layout.
Example
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
....
//Edit your layout
</RelativeLayout>
U have to keep edit and arrange until the design is what you like.
However, I believe there is a lot of tutorial You can learn from Youtube. Check it Out.

Android studio programming

I am developing an android application to display current news or events. But, starting the interface with the toolbar and the login page, I have a problem with ConstraintLayout. I do not know why but the textview and imageview are red while in RelativeLayout and LinearLayout it works.
<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.exemple.rivoramampiandra.appsname.MainActivity">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Connexion"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.079" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="match_parent" />
<EditText
android:id="#+id/editText"
android:layout_width="367dp"
android:layout_height="wrap_content"
android:ems="10"
android:inputType="textPersonName"
android:text="Name"
tools:layout_editor_absoluteX="9dp"
tools:layout_editor_absoluteY="85dp" />

Seeing your code would help a lot in solving the problem, some guesses though might be:
Constraints were not added to the TextView and ImageView as each view place in the UI must be constrained to its parent or child in some way
https://developer.android.com/training/constraint-layout/index.html#add-a-constraint
If you converted the ConstraintLayout to a RelativeView or a LinearLayout. It is possible the attributes are left in the XML of the constrained attributes within the children views inside your layout. thosapp:layout_constraintBaseline_toBaselineOf="#+id/text_title"
https://medium.com/exploring-android/exploring-the-new-android-constraintlayout-eed37fe8d8f1
Hope any of this solved your problem!