How do I create a transparent Activity on Android?

Add the following style in your res/values/styles.xml file (if you don’t have one, create it.) Here’s a complete file:

<?xml version="1.0" encoding="utf-8"?><resources>  <style name="Theme.Transparent" parent="android:Theme">    <item name="android:windowIsTranslucent">true</item>    <item name="android:windowBackground">@android:color/transparent</item>    <item name="android:windowContentOverlay">@null</item>    <item name="android:windowNoTitle">true</item>    <item name="android:windowIsFloating">true</item>    <item name="android:backgroundDimEnabled">false</item>  </style></resources>

(The value @color/transparent is the color value #00000000 which I put in the res/values/color.xml file. You can also use @android:color/transparent in later Android versions.)

Then apply the style to your activity, for example:

<activity android:name=".SampleActivity" android:theme="@style/Theme.Transparent">...</activity>

It goes like this:

<activity android:name=".usual.activity.Declaration" android:theme="@android:style/Theme.Translucent.NoTitleBar" />

In the styles.xml:

<style name="Theme.AppCompat.Translucent" parent="Theme.AppCompat.NoActionBar">    <item name="android:background">#33000000</item> <!-- Or any transparency or color you need -->    <item name="android:windowNoTitle">true</item>    <item name="android:windowBackground">@android:color/transparent</item>    <item name="android:colorBackgroundCacheHint">@null</item>    <item name="android:windowIsTranslucent">true</item>    <item name="android:windowAnimationStyle">@android:style/Animation</item></style>

In the AndroidManifest.xml:

<activity    android:name=".WhateverNameOfTheActivityIs"    android:theme="@style/Theme.AppCompat.Translucent">    ...</activity>