Develop Reference

Android: Button is faded gray when it should be transparent

I want a basic button that has a completely transparent background (so the only thing visible is the text.)
As per other answers, I've set android:background="#0000", but still, it has a faded gray color.
Here is the complete layout code:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#3176C0">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#0000"
android:text="TRANSPARENT?" />
</RelativeLayout>
What it looks like:
What I want:

Turns out that it is not a background showing, but a shadow from the default button style.
Therefore, the answer is that the button style needs to be changed by adding this to the button:
style="?android:attr/borderlessButtonStyle"

Try this code ...
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#null"
android:text="Transparent"/>

Answer is borderlessbutton.
Refer: https://developer.android.com/guide/topics/ui/controls/button#Borderless

Try this:
android:background="#android:color/transparent"

Shadow on floating action button

For some reason a small shadow appears on top of my floating action button as seen here but only on the debugging device but not in the Android Studio preview.
The button is nested in a relative layout to position it in the bottom of the screen like this:
<?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"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:layout_margin="16dp"
android:src="#drawable/baseline_play_circle_outline_white_36" />
</RelativeLayout>
Update:
This is what it looks like when clicked.
The problem is also caused by adding an alpha value to the FAB like here
but in my case, as the shadow color is almost the same as the original, adding 0.9 alpha makes it way less obvious.

try adding following attributes to fab :
android:clipChildren="false"
android:clipToPadding="false"

last button in layout doesn't have elevation

I'm working with Android Lollipop.
I have this layout:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/buttonlayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="#dimen/spacing_normal"
android:orientation="vertical" >
<Button
android:id="#+id/facebook_button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
style="#style/FacebookButton" />
<com.myCompany.views.widgets.CustomTextView
android:id="#+id/or_textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="#dimen/spacing_normal"
android:layout_marginBottom="#dimen/spacing_normal"
android:text="#string/app.widget.connexion.or"
app:font_name="Roboto-Medium.ttf" />
<Button
android:id="#+id/myCompany_button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
style="#style/myCompanyButton" />
the two style applied to the buttons are simply ripple effect with different background colors. The thing is the first button has an elevation with a shadow when we click it and the second hasn't unless I add an other widget below him. I suppose it's due to the ripple effect and because I had to change the background attribute, but I don't know how to make the effect back.
I tried to use translationZ and elevation attribute, but it didn't work (or I failed to use them properly).
any ideas ?

Android: Strange gap between buttons

I am just beginning with Android. I am making a layout with buttons, but a very strange thing is happening — there is a small gap between them. Setting margin and padding to 0 is also not helping.
Here is my simple layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:orientation="vertical">
<Button
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"/>
<Button
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"/>
</LinearLayout>
It is looking like this:

Make your own flat Button style with ripple effect [lollipop] and without it [pre-lollipop]:
https://gist.github.com/dmytrodanylyk/3513e42839ae4309d2b5

You have to use android:background to change the background of button. For example if you use android:background = "#FFFFFF" your visual problem is fixed. In reality , there is no space between the buttons, their background creates an "illusion"

Radio Button Text over Button

I'm trying to create a view in android that looks like:
Text
Radio Button 1
...
...
I thought it was simple enough but at least in the layout preview and emulator I'm seeing the text for the RadioButton appear on top of the actual radio button (the circle), see the attached screen shot. I'm guessing this is something very trivial but I'm messed around with gravity and every other setting I can think of and nothing. Android 3.1 if that matters.
Here's my layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:background="#color/white"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView android:id="#+id/question_text"
android:textColor="#color/primary_gray"
android:layout_width="match_parent"
android:text="XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
android:layout_height="wrap_content"/>
<RadioGroup android:id="#+id/multiple_choice_one_answer_group"
android:background="#color/white"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RadioButton
android:background="#color/primary_gray"
android:textColor="#color/black"
android:textSize="10sp"
android:text="XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" />
</RadioGroup>
</LinearLayout>
Screenshot:

The problem is setting the background. If you remove the background from the RadioButton and keep it on the RadioGroup, it has the effect you're looking for. In general, setting the background of a Button to everything removes the button look; try it on a regular Button and you'll see. This is because the background for a Button is already set to something, and you're replacing it with a flat color.
Try this instead:
<RadioGroup android:id="#+id/multiple_choice_one_answer_group"
android:background="#color/primary_gray"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RadioButton
android:textColor="#color/black"
android:textSize="10sp"
android:text="XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" />
</RadioGroup>

Setting the background in the java code instead of the layout solves this as well.