I want to change basicTheme instead of the initial thing "Theme.Black.NoTitleBar.Fullscreen."

I spent all day finding the way to change the theme.

The reason why I did this thing is to change the style of “AlertDialog” I used in the game.

These are what I tried to do.

A. styles.xml in ‘values’ folder
In order to get rid of the basic theme style,
I changed it

<style name=“UE4BaseTheme” parent = “@android:style/Theme.Black.NoTitleBar.Fullscreen” />

to

<style name=“UE4BaseTheme”>
<item name=“android:windowNoTitle”>true</item>
<item name=“android:windowFullscreen”>true</item>
</style>

B. styles.xml files in values-land and values-port folders
I removed this line below.
<style name=“UE4BaseTheme” parent = “@android:style/Theme.Black.NoTitleBar.Fullscreen” />

Not work at all!!!

I must miss something.

Anyone help me. Thanks.

For anyone looking for a solution, here’s what I’ve found so far:

When building Android apk, Unreal generates AndroidManifest.xml under Intermediate/Android/arm64. Inside that file, you can check the Android activity declarations. Both SplashActivity and GameActivity is using android:theme="@style/UnrealSplashTheme".

There are two options to modify that:

  1. Update AndroidManifest via UPL
    Got inspired from this post. I added this to the UPL.xml file.
<androidManifestUpdates>
    <removeAttribute tag="activity" name="android:theme"/>
    <addAttribute tag="activity" name="android:theme" value="@style/Theme.AppCompat.NoActionBar"/> 
</androidManifestUpdates>
  1. Override styles.xml file
    During the build process, Unreal will actually copy anything under Build/Android/ to Intermediate/Android/arm64 and override template files. For example, if you set custom App icons, you’ll see it added to Build/Android/res/drawable and then copied over to Intermediate.
    So similarly, you can create Build/Android/res/values/styles.xml and Build/Android/res/values-land/styles.xml to override the styles.xml file. Editing the files in Intermediate folder doesn’t work as they always gets regenerated in the build process! I would just copy files from Intermediate and modify them. This gives you more flexibility to control the style.

That being said, I did encounter another issue after changing theme from @style/Theme.Black.AppCompat.NoActionBar.FullScreen to @style/Theme.AppCompat.NoActionBar. The touch positions are off. They don’t account for the action bar or navigation bar. If anyone has ideas how to fix this, that would be great!