I'm trying to create view with button and fragemtn with list under this button. The problem is that the list starts from top of button not from bottom and it's look like this:
Layout code:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".activities.BluetoothActivity">
<Button
android:text="#string/scan"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/BluetoothScanButton"
app:layout_constraintEnd_toEndOf="parent"
android:layout_marginEnd="8dp"
app:layout_constraintStart_toStartOf="parent"
android:layout_marginStart="8dp"
android:layout_marginTop="40dp"
app:layout_constraintTop_toTopOf="parent"/>
<fragment
android:id="#+id/BluetoothDevicesFragment"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:name="com.tatara.taffico.DeviceListFragment"
app:layout_constraintEnd_toEndOf="parent"
android:layout_marginEnd="8dp"
app:layout_constraintStart_toStartOf="parent"
android:layout_marginStart="8dp"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginTop="8dp"
app:layout_constraintTop_toBottomOf="#+id/BluetoothScanButton"/>
</android.support.constraint.ConstraintLayout>
Could anyone help me to fix it ?
You should add android:layout_height="0dp" fragment section.
<fragment
android:id="#+id/BluetoothDevicesFragment"
android:layout_width="match_parent"
android:layout_height="0dp"
ConstraintLayout
You can also define one dimension of a widget as a ratio of the other
one. In order to do that, you need to have at least one constrained
dimension be set to 0dp (i.e., MATCH_CONSTRAINT).
I believe you're missing app:layout_constraintBottom_toTopOf="#id/BluetoothDevicesFragment" in the Button.
Related
I can´t understand constraints behaviour. Take a look to this layout
<?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="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="#+id/button"
android:layout_width="0dp"
android:layout_height="0dp"
android:background="#color/purple_200"
android:text="whatever"
app:layout_constraintDimensionRatio="w, 1:1"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
It is supposed 0dp mean all available space. This button has both dimensions 0dp and a 1:1 ratio. And it is aligned left and top with parent so I guess it will be showing a square with a parent width as a side. But it is showing something unexpected for me, just a point on the upper left corner (even it is having some text):
It is clear I am not understanding this layout properly. Please enlighten me
You need to add to more constraints in order to work
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
If you are using 0dp for height, you need to constraint both top and bottom and vice versa
Copy and past this
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="#+id/btn"
android:layout_width="126dp"
android:layout_height="53dp"
android:text="Button"
android:textSize="20sp"
android:textStyle="bold"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
i think you need to add more Constraint!
add this :
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
for this case, it will must like this :
<Button
android:id="#+id/button"
android:layout_width="0dp"
android:layout_height="0dp"
android:background="#color/purple_200"
android:text="whatever"
app:layout_constraintDimensionRatio="w, 1:1"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
hope this help you, have a great day! don't forget to take coffe time!
Stay Coding and Stay Awesome!
Image view is hiding under the button what changes I can do so that the image view can be above the button view pager also have bottom padding so that button can properly accommodate. The image is showing on the other parts but not above the button.
<?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"
android:orientation="vertical"
tools:context=".McqActivity"
android:id="#+id/fragment"
>
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent">
<ImageView
android:id="#+id/starFirst"
android:layout_width="50dp"
android:layout_height="50dp"
android:src="#drawable/ic_baseline_star_24"
/>
<com.google.android.material.button.MaterialButton
android:id="#+id/right"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
</RelativeLayout>
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/questions_view_frag"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0"
android:orientation="horizontal"
android:paddingBottom="20dp"
android:paddingTop="50dp"
>
</androidx.viewpager2.widget.ViewPager2>
</androidx.constraintlayout.widget.ConstraintLayout>
layout_constraintBottom_toBottomOf and other layout_constraint... won't work inside RelativeLayout, these are desired to work with ConstraintLayout as strict parent. if you want to align two Views next to/below/above inside RelativeLayoyut you have to use other attributes, e.g.
android:layout_below="#+id/starFirst"
android:layout_above="#+id/starFirst"
android:layout_toRightOf="#id/starFirst"
android:layout_toLeftOf="#id/starFirst"
note that every attr which starts with layout_ is desired to be read by strict parent, not by View which have such attrs set. every ViewGroup have own set of such
edit: turned out that this is an elevation case/issue (Z axis), so useful attributes are
android:translationZ="100dp"
android:elevation="100dp"
I'm new to Android development. I created an activity/layout with two views. The first one is a custom button that I want to be 50dp high. The second is a list view that I want to take the rest of the screen below it.
My problem is that when I constrain them to each other, the ListView gets crushed to 0 and the "springs" around the 50dp button expand to take all the space. Here I've given the list a height of 200dp so you can see it. If I set it to "match constraint" it goes to 0. There is content in the list.
With iOS constraints I know how to do this. The constraints around the button are behaving like "greater than or equal" constraints in iOS. I want them to be "equal". How do you do this in Android?
Here's the XML.
<?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="match_parent"
android:layout_height="match_parent"
app:layout_constrainedHeight="false"
tools:context=".WorkoutActivity">
<mycompany.PlayPauseButton
android:id="#+id/play_pause_button"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_marginTop="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintBottom_toTopOf="#+id/workout_list"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ListView
android:id="#+id/workout_list"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
You have to attach the top of listView to the bottom of playButton not other way around
<?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="match_parent"
android:layout_height="match_parent"
app:layout_constrainedHeight="false"
tools:context=".WorkoutActivity">
<mycompany.PlayPauseButton
android:id="#+id/play_pause_button"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_marginTop="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ListView
android:id="#+id/workout_list"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_margin="8dp"
app:layout_constraintTop_toBottomOf="#id/play_pause_button"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
Cheers :)
Since you want the ListView to occupy all of the available space, it is a good idea to set the height to 0dp. This is sorta like a stretch-me-how-you-like scheme for ConstraintLayouts. The height would therefore entirely depend on the top and bottom constraints. So, nice step!
Your mistake, however, was the way you constrained your views. You were supposed to constrain the ListView to the bottom of play_pause_button (as shown below). This way, the position of the ListView is always dependent on (and below) playButton.
<?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="match_parent"
android:layout_height="match_parent"
app:layout_constrainedHeight="false"
tools:context=".WorkoutActivity">
<mycompany.PlayPauseButton
android:id="#+id/play_pause_button"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_marginTop="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ListView
android:id="#+id/workout_list"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_margin="8dp"
app:layout_constraintTop_toBottomOf="#id/play_pause_button"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
I hope this helps. Merry coding!
Just set the constraints the right way. No constraint bottom in the button but a constraintTop in the listview.
<?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="match_parent"
android:layout_height="match_parent"
app:layout_constrainedHeight="false"
tools:context=".ui.MainActivity">
<mycompany.PlayPauseButton
android:id="#+id/play_pause_button"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_marginTop="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ListView
android:id="#+id/workout_list"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/play_pause_button"/>
</androidx.constraintlayout.widget.ConstraintLayout>
this is working for me :
<?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="match_parent"
android:layout_height="match_parent"
app:layout_constrainedHeight="false">
<mycompany.PlayPauseButton
android:id="#+id/play_pause_button"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_marginTop="8dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"/>
<ListView
android:id="#+id/workout_list"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginStart="8dp"
android:layout_marginEnd="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" android:layout_marginTop="8dp"
app:layout_constraintTop_toBottomOf="#+id/play_pause_button"/>
</androidx.constraintlayout.widget.ConstraintLayout>
With constraint layout, it's usually (at least in my experience) a lot easier to build either top-down or bottom-up, so get one component into a position where you're happy with it and then add then next one, maybe that helps
I'm facing issues with constraintlayout when placing ImageView or FrameLayout on top of a Button.
When i try to inflate a fragment on FrameLayout, Buttons that are part of activity are visible on top of fragment UI.
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="button"/>
<FrameLayout
android:background="#color/blue"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
</android.support.constraint.ConstraintLayout>
To place any view above another view you have to give proper constraint like below.
Give top and bottom constraint proper and also as I give all constraint(start,end,top,bottom) to FrameLayout it's height and width give to 0dp(you can't use height to match_parent otherwise it's cover whole screen and overlap button).
>
<?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"
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:text="button"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toBottomOf="parent"/>
<FrameLayout
android:background="#color/colorPrimary"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toTopOf="#+id/button"/>
</android.support.constraint.ConstraintLayout>
To set constraints of button and FrameLayout to,
Button:
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
FrameLayout :
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/button"
Your code looks ok but if you want to tell 1 view to be above another view in ConstraintLayout you can go to the design tab and move the higher above the lower view:
Example:
In the image, you can see that the button is placed below the frameLayout so he will be lower than the frameLayout (the frameLayout will be above the button)
Also, you were missing some constraints on your button :
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="button"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="#+id/frameLayout2" />
<FrameLayout
android:id="#+id/frameLayout2"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
And if all that didn't help you check this thread, as #Xavier Rubio Jansana said, it may be because of elevation.
Try the code below
<?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">
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:text="button"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<FrameLayout
android:layout_width="match_parent"
android:layout_height="638dp"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:layout_marginBottom="8dp"
android:background="#color/appGrey"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/button">
</FrameLayout>
</android.support.constraint.ConstraintLayout>
My problem is that the controls (checkboxes, buttons etc) which I have placed are not visible on my emulator.
Below is my XML file:
<?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=".MainActivity">
<Button
android:id="#+id/btn1"
android:layout_width="match_parent"
android:layout_height="52dp"
android:text="#string/btn1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
tools:ignore="MissingConstraints"
tools:layout_editor_absoluteY="0dp" />
<Button
android:id="#+id/btn2"
android:layout_width="match_parent"
android:layout_height="77dp"
android:text="#string/btn2"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
tools:ignore="MissingConstraints"
tools:layout_editor_absoluteY="68dp" />
<fragment
android:id="#+id/fragment"
android:name="com.example.mypc.fragmentactivity.Fragment1"
android:layout_width="222dp"
android:layout_height="285dp"
android:layout_marginBottom="40dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
tools:ignore="MissingConstraints" />
Here is my XML (design view):
Here is my emulator window:
Is there is something wrong in my XML file?
Please provide me solution for this.
How should I handle this?
You are using ConstraintLayout without relative positioning.
According to developer site:
Relative positioning is one of the basic building blocks of creating layouts in ConstraintLayout. Those constraints allow you to position a given widget relative to other. You can constrain a widget on the horizontal and vertical axis:
Horizontal Axis: left, right, start and end sides
Vertical Axis: top, bottom sides, and text baseline
Here is the solution which may help you:
<?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=".MainActivity">
<Button
android:id="#+id/btn1"
android:layout_width="match_parent"
android:layout_height="52dp"
android:text="#string/btn1"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toBottomOf="#id/btn2"/>
<Button
android:id="#+id/btn2"
android:layout_width="match_parent"
android:layout_height="77dp"
android:text="#string/btn2"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="#id/btn1"
android:layout_marginTop="10dp"/>
</android.support.constraint.ConstraintLayout>
I have used relative positioning to solve the problem. If you are using constraint layout then without relative positioning your views will get overlap with each other.
Because you didn't align properly the second button. it seems like second button overlap first one.
try this one
<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=".activites.HomeActivity"
android:layout_margin="6dp">
<Button
android:id="#+id/btnOne"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:text="Button One"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="#+id/btnTwo"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:text="Button Two"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/btnOne" />
<fragment
android:id="#+id/fragment"
android:layout_width="222dp"
android:layout_height="285dp"
android:layout_marginBottom="40dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/btnTwo"
tools:ignore="MissingConstraints" />
</android.support.constraint.ConstraintLayout>
output would be like this
In your code your elements are overflowing each other at one position that is why they are not visible.
My suggestion is do not constraint Layout at initial stage of learning android.
Use Linear Layout in place of constraint Layout.
Since in constraint Layout Layout Editor uses constraints to determine the position of a UI element within the layout. You have to give many constraint XML attributes like.
app:layout_editor_absoluteX="73dp"
app:layout_editor_absoluteY="176dp"
app:layout_constraintLeft_creator="1"
app:layout_constraintTop_creator="1"
app:layout_constraintRight_creator="1"
to specify the position of elements in layout.
Use Linear Layout in place of Constraint Layout and give
orientation:"vetical"
to view all your elements.
The layout_editor attributes are only used for the editor preview and have no effect on the final layouts. You should position your elements using the ConstraintLayout specific attributes.
It's used to just for preview purpose.
tools:layout_editor_absoluteY="68dp"
Simply use LinearLayout instead of ConstraintLayout. Also provide orientation vertical to that LinearLayout.
It will helps you
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
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">
<Button
android:id="#+id/btn1"
android:layout_width="match_parent"
android:layout_height="52dp"
android:text="#string/btn1" />
<Button
android:id="#+id/btn2"
android:layout_width="match_parent"
android:layout_height="77dp"
android:text="#string/btn2" />
<fragment
android:id="#+id/fragment"
android:name="com.example.mypc.fragmentactivity.Fragment1"
android:layout_width="222dp"
android:layout_height="285dp"
android:layout_marginBottom="40dp" />
</LinearLayout>