Android Question [Solved] Blank screen when starting any application created with B4A (Android 11)

[vecino]

Hi, on a new 10" tablet with Android 11 I am having that problem with any application created with B4A.
Even also the "B4A Bridge" app has that problem.
Even with an application that has only one button.
Usually the whole screen goes blank, and if I hit the "back key" it exits (sometimes) and if I try to enter again then sometimes it starts fine (sometimes).
I have downloaded, for testing purposes, from the google store several apps and they all work fine.
I'm lost!!! I don't get it, it's 6 tablets the same.
I have seen this thread which is similar to what is happening to me:
What could be going on?

 

[vecino]

There is a function in the B4A Library B4ActivityManager: detect bots using your app

What is the result of the log when you run the test program of this library?

Yes, it has 2 Gb but the problem is that the google store apps all work fine.

 

[kimstudio]

From what I read I will say the problem is from the Go Edition, so maybe find another forumer who has this version to test.

 

[Alexander Stolte]

now we know, its android go

 

[MicroDrie]

Yes, it has 2 Gb but the problem is that the google store apps all work fine.

Every app is different and uses different rights and techniques. It seems that B4A-Bridge wants to use something that is blocked on your tablet.

In this forum you can find a somewhat vague rights for WiFi connection on Andro 10 Go. That is why it is interesting to see if it goes well via a USB connection, because then the WiFi connection (rights) remains.

 

[vecino]

Thank you, friends.
Apart from the memory, b4a bridge, usb connection, etc.
The real problem is that when I start my program it comes up with a blank screen. And sometimes, when exiting and restarting then it comes up fine.
And that only happens with my programs made with B4A and it happens also with "b4a bridge" which is surely made with B4A.
That is the problem.

 

[aeric]

So maybe you should add something in the manifest editor to tell that the app is targeting Android (Go Edition).

<uses-feature android:name="android.hardware.ram.low" android:required="true">

Detecting Android Go phones

I have developed an application but now I would like to check at the first startup of the app if it is an Android Go phone and if so, inform the user that it is not supported. In Android it is pos...

stackoverflow.com

 

[Mahares]

And that only happens with my programs made with B4A and it happens also with "b4a bridge" which is surely made with B4A.
That is the problem

In that case you really need to address your posts directly to Erel and have him comment on this lengthy thread

 

[vecino]

The screen is still blank the first time

 

[teddybear]

I always think the problem is in starter module, try removing it.

 

[agraham]

Give up on those crap tablets. You are not going to find a fix. No-one else has had the same problems with Android 11 in the hundreds of thousands of device hours that B4A apps must have now accumulated. The single common factor is your Chinese junk.

 

[vecino]

Give up on those crap tablets. You are not going to find a fix. No-one else has had the same problems with Android 11 in the hundreds of thousands of device hours that B4A apps must have now accumulated. The single common factor is your Chinese junk.

Yes, perfect, I will do that, but why do all the programs I have tried from the "play store" work?
There have been 20 o 30 apps for photos, graphic editing, games, lose weight, weather station, etc. etc. etc.

 

[agraham]

but why do all the programs I have tried from the "play store" work?

We don't know. We will probably never know without low level debugging tools we do not possess. But as the OS is burnt into ROMs on the device it is probably unfixable anyway so just move on for God's sake.

 

[vecino]

What do I tell my customer now?
Excuse me, but my programs and all the ones that are made with the IDE that I use, do not work on these tablets that I have sold you.

 

[agraham]

That appears to be the reality of it.

 

[vecino]

That appears to be the reality of it.

:/

 

[aeric]

The screen is still blank the first time

Can you show a new B4XPage when the app started (B4XPage_Created or Appear)? If you are using Activity, start a new Activity?

 

[vecino]

To test, I have changed openjdk 11 for java oracle 8 and the result is the same: white screen the first time and sometimes it works fine at the second try.

I don't remember if I have commented it at some point, for what it's worth, when starting and connecting "b4a bridge", when compiling any project it comes out on the tablet screen (b4a bridge):
"Error writing file." and then "Error saving APK".

 

[vecino]

Can you show a new B4XPage when the app started (B4XPage_Created or Appear)? If you are using Activity, start a new Activity?

No nothing, just a blank screen.
I have to exit with the android "back key" and try to start the program again.
In some programs that key doesn't work either and you have to use the center key, the round key.

 

[moty22]

I'm sure it's 11 Go edition. I have Alcatel phone that has 11 Go and the USB doesn't read serial device or flash drive. It is not a drive problem, the hardware doesn't generate 5V to operate USB device, if you plug in a USB flash with a light in it you will see that it doesn't come on. It is also true that RAM under 2GB works with Go only.

 

[MicroDrie]

As I wrote before, it's most likely the tablet. Most of all, the application goes into a kind of "timer" or "sleep" mode. Unfortunately, it's a cross-out list in the hope that you find the cause of the problem. Unfortunately, it's a cross-out list in the hope that you find the cause of the problem.
Did you try turning off battery optimization for the B4A-Bridge and your apps won’t put your apps to sleep. Here’s how to turn off battery optimization for an app on Android 10: Open the Settings app, and then tap Apps %notifications > Advanced > Special app access > Battery optimization > Not optimized (in the drop-down menu) > All apps. Now tap the app’s name (you can search it using the search button in the top right).

What is the result of turning off battery optimization for B4A-Bridge and your app(s)?