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?

 

[walterf25]

After all this, it would be good for you to post the unfiltered logs, specially when you start the app the first time and the screen shows blank, it would be interesting seeing what the logs spit out, also you should try inserting some logs before the layout is loaded and after the layout is loaded.

Walter

 

[Erel]

Do you see this problem with the "splash" example: https://www.b4x.com/android/forum/threads/b4x-b4xpages-splash-screen.120851/#content ?

 

[vecino]

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.

Can you try this application?
https://intitec.com/actualizaciones/test/preventa.apk
It's just to check that it starts normally and no blank screen comes up the first time.
Other folks have tried it and it worked fine for them, but in my case I have that problem and that is what this forum thread is trying to fix.
There is nothing special or intrusive about it, you can uninstall it normally afterwards.
Thanks.

 

[walterf25]

Can you try this application?
https://intitec.com/actualizaciones/test/preventa.apk
It's just to check that it starts normally and no blank screen comes up the first time.
Other folks have tried it and it worked fine for them, but in my case I have that problem and that is what this forum thread is trying to fix.
There is nothing special or intrusive about it, you can uninstall it normally afterwards.
Thanks.

This is what it looks on my end.

 

[vecino]

Do you see this problem with the "splash" example: https://www.b4x.com/android/forum/threads/b4x-b4xpages-splash-screen.120851/#content ?

Hello, it happens exactly the same as with the other programs, with the difference that the screen has not come out white, it has come out blue, completely.
I clicked on "android back key" and again I clicked on the icon to start the program. This second time it did show the screen with a splash and then a button.

But, as I say, the application has done the same as the rest of B4A applications, the first time shows all the white screen (blue in this case) and the second time has worked fine.

 

[vecino]

This is what it looks on my end.

Thanks, and it worked right the first time? didn't you get a blank screen the first time you ran the application?

 

[walterf25]

Thanks, and it worked right the first time? didn't you get a blank screen the first time you ran the application?

Worked fine right away the first time, no blank screen.

 

[moty22]

Can you try this application?

Your program loads and runs OK on my Alcatel 11 Go. When settings-system-about phone it displays "Android version 11" (it doesn't say Go)
The B4X Bridge v2.62 works and I can load programs from B4A v10.2. I can connect to B4X via USB and wifi but it warns that "display over other app" function doesn't work. Connecting SerialUSB doesn't work, any OTG doesn't work.
To my opinion Go edition is an embedded OS and the manufacturer can delete any part he likes. USB requires 5V 500mA which is a problem for small battery.

 

[vecino]

Your program loads and runs OK on my Alcatel 11 Go. When settings-system-about phone it displays "Android version 11" (it doesn't say Go)
The B4X Bridge v2.62 works and I can load programs from B4A v10.2. I can connect to B4X via USB and wifi but it warns that "display over other app" function doesn't work. Connecting SerialUSB doesn't work, any OTG doesn't work.
To my opinion Go edition is an embedded OS and the manufacturer can delete any part he likes. USB requires 5V 500mA which is a problem for small battery.

Thanks for the information, I am glad my program worked well. I'm a little uneasy because I'm going to have to buy other tablets to replace these, and I don't want to run into the same problem.

 

[moty22]

Try several settings in system-developer options, maybe some settings will make a difference. It can be very difficult to make sure it's not Go edition unless you buy from known firm. Better luck next time.

 

[moty22]

Do you see this problem with the "splash" example: https://www.b4x.com/android/forum/threads/b4x-b4xpages-splash-screen.120851/#content ?

Erel, hope you are paid for the overtime.

 

[Erel]

B4A apps wait for the activity size to be set before Activity_Create runs.
For some reason your tablet misbehaves and the reported size is not set as expected.

This is not a common issue.

 

[vecino]

B4A apps wait for the activity size to be set before Activity_Create runs.
For some reason your tablet misbehaves and the reported size is not set as expected.

This is not a common issue.

Hello, is there a solution for that?
Even if it is a temporary "patch".
There must be something to try.

I cannot tell my customers that all applications work well, but none of those made with B4A work. And I use B4A. The client will answer that this is my problem, that I spend money on other tablets or that I return his money and he will look for another company that suits him the software.

 

[Sandman]

For some reason your tablet misbehaves and the reported size is not set as expected.

Given the very wide range of android devices out there, I suspect this could happen to anyone of us here in the forum.

Is there a way for us to detect this type of device misbehaviour so we don't have to fall into the same confusing hole as vecino found himself in?

 

[Sandman]

Even if it is a temporary "patch".

Amateur guess: Perhaps it's possible to comment out the "wait for the activity size to be set" in the generated java code and then manually compile the whole thing? I wouldn't know how to do that, though. And I have zero insight into what other issues might be caused for other devices. So take this with a really big grain of salt. I thought I'd mention it, in case you were desperate enough...

 

[teddybear]

What's your tablet brand and model?

 

[Erel]

Create a new B4XPages project.
Run it in release mode.
Assuming that you see a white screen, please post the filtered logs.

 

[vecino]

What's your tablet brand and model?

SPC GRAVITY SE [2ª Gen]

Tablet de 10,1 pulgadas con tecnología IPS y bordes más reducidos para un cuerpo compacto y un agarre cómodo. Memoria interna de 32GB ampliable y 2GB de RAM.

www.spc.es

But I have sold lots of tablets of that brand and they have all worked well.
The problem is these 6 of this model that I bought for a customer.

 

[teddybear]

Did you try removing starter module?

 

[vecino]

Create a new B4XPages project.
Run it in release mode.
Assuming that you see a white screen, please post the filtered logs.

Yes, it showed the white screen the first time (blue in this case) and the second time it started fine.

Filtered:

Logger connected to: SMART PRODUCTS CONNECTION SA GRAVITY SE
--------- beginning of main

No filtered:

Logger connected to: SMART PRODUCTS CONNECTION SA GRAVITY SE
--------- beginning of main
Not starting debugger since process cannot load the jdwp agent.
Returning zygote-cached class loader: /system/framework/android.test.base.jar
No Network Security Config specified, using platform default
No Network Security Config specified, using platform default
common created.
Bridge logger not enabled.
[MapperLoader] load
[MapperLoader] loadModule
ignoring event: create_menu
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
Not starting debugger since process cannot load the jdwp agent.
Returning zygote-cached class loader: /system/framework/android.test.base.jar
No Network Security Config specified, using platform default
No Network Security Config specified, using platform default
common created.
Bridge logger not enabled.
[MapperLoader] load
[MapperLoader] loadModule
ignoring event: create_menu
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
Not starting debugger since process cannot load the jdwp agent.
Returning zygote-cached class loader: /system/framework/android.test.base.jar
No Network Security Config specified, using platform default
No Network Security Config specified, using platform default
common created.
Starting remote logger. Port: 35352
[MapperLoader] load
[MapperLoader] loadModule
After accept
ignoring event: create_menu
ignoring event: activity_keypress
ignoring event: activity_keypress
ignoring event: activity_keypress
Log reader error: java.io.InterruptedIOException: read interrupted
-1 received
writer error
java.lang.InterruptedException
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.reportInterruptAfterWait(AbstractQueuedSynchronizer.java:2042)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2076)
at java.util.concurrent.ArrayBlockingQueue.take(ArrayBlockingQueue.java:387)
at anywheresoftware.b4a.remotelogger.Connector$Writer.run(Connector.java:160)
at java.lang.Thread.run(Thread.java:923)
Starting remote logger. Port: 35352
After accept