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How to fix crash handling in android 10

I have a Unity Scene built with Cardboard SDK and exported as a library for Android. The library is used to play videos in cardboard mode on the android app. it's not the whole app, but a part in it. The rest of the android app is built with Kotlin and Java.
I have implemented that and all the functions work as expected, but, exiting the scene crashes the android.
We tried various ways to clear player prefs and even clear memory before closing the scene. But on android it always crashes. I have two android phones with android 9 and 10 for testing.
In the android app, I have made it such that as soon as the app crashes, I try to recover. My crash is that some lateinit var variables are destroyed. Their value becomes null and recovering the previous activity crashes it. So right after I exit the unity scene, I load the dereferenced variables back into memory and everything works again.
Note: I have tried using Application.Quit(); in unity, but it just closes the whole app. On the other hand, I only want to close the running scene
In unity [I call a function goBack in android part to close the app]:
public void GoToHome()
{
Pause();
Stop();
Resources.UnloadUnusedAssets();
PlayerPrefs.DeleteAll();
AndroidJavaClass jc = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
AndroidJavaObject jo = jc.GetStatic<AndroidJavaObject>("currentActivity");
jo.Call("goBack");
}
In App:
public void goBack()
{
UnityPlayer.currentActivity.finish();
finish();
loadDerereferencedVars();
}
This goes perfectly on android 9. On the other phone with android 10, after I close the scene, the app continues to function, but, there comes a message
When I click close app, the app continues to work.
I have checked the logs and there is a null pointer dereference cause for the crash in Unity Main >...
If you'd like to see the Unity Crash Log from LogCat in Android Studio
So, since the app is still running, I thought, it would be better to just hide the crash report and just let the user not know about this crash, but still report it.
I tried enclosing my app in Application and added a method to catch uncaughtException.
here is my application class:
public class MyApp extends Application {
private static final String TAG = "MyAPP";
#Override
public void onCreate() {
super.onCreate();
Thread.setDefaultUncaughtExceptionHandler(
new Thread.UncaughtExceptionHandler() {
#Override
public void uncaughtException (Thread thread, Throwable e) {
handleUncaughtException (thread, e);
}
});
}
/**
* Handles Uncaught Exceptions
*/
private void handleUncaughtException (Thread thread, Throwable e) {
// The following shows what I'd like, though it won't work like this.
Toast.makeText(getApplicationContext(), "Looks like I am having a bad day!", Toast.LENGTH_LONG).show();
Log.e("UncaughtException", "I found an exception!");
// Add some code logic if needed based on your requirement
}
}
Again, this works perfectly in Android 9 and I also got the error reported. However in the phone with android 10, I just get the crash report like the image above and no error is reported.
I want to know why the crash handling is not working and how can I fix it?

I would not finish the Activity you came from, instead just open a new intent (on UnityActivity). When you end this intent the app will come back to the last active Activity.
I will give you my script as an example:
public void sendJobToUnity(String fileName, boolean isNewJob){
//creates a new job. It exists inside the JobSelector Activity
isUnityLoaded = true;
//this is what you are looking for part1
Intent i = new Intent(JobSelector.this, MainUnityActivity.class); //same as (CurrentActivity.this, UnityActivity.this)
//those are how I send some data across the app. just ignore it
//i.putExtra("jobName", fileName);
//i.putExtra("isNewJob",isNewJob);
//i.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivityForResult(i, 1); //this is what you are looking for part2
}
For closing it, in the MainUnityActivity Activity I have an override that Unity sends to Android in order to Unload the activity (not quit it completely cause you cannot load it again if you do it) like this:
#Override
protected void receiveJobAndUnloadUnity(String data){
saveCurrentJob(data); //saves the job it receives from Unity
mUnityPlayer.unload(); //this is what you are looking for part3
}
If you want to unload Unity from android you can put "mUnityPlayer.unload();" wherever you want, provided you have started the Activity the way I've shown you.
Note that "mUnityPlayer" is a default Unity variable and cannot be renamed

How to change a photo?

I am trying to change photos in android studio by clicking on my button.
When I put code for changing the photo in my MainActivity.java I keep getting this type of error messages and it says :
Cannot resolve symbol "image"
image.setImageResource(R.drawable.xxx);
I am watching Udemy course for android development and I have done everything same like the professor on that video.
I have tried to restart android studio.
I have tried to make new project.
I have tried to clear invalidate caches and restart.
public void changeImage(View view)
{
ImageView bitcoin = findViewById(R.id.bitcoin);
image.setImageResource(R.drawable.xxx);
}
I hope there is actual error with android studio,because code is clone of the video that I am watching.

You are binding your layout's ImageView in Java file with bitcoin variable and you are trying to set an image on an unknown variable 'image'(maybe it's not defined in the class). So you have to set as below.
ImageView bitcoin = findViewById(R.id.bitcoin);
bitcoin.setImageResource(R.drawable.xxx);

Set Your Code Like this
ImageView image = findViewById(R.id.bitcoin);
image.setImageResource(R.drawable.xxx);

change your this line
image.setImageResource(R.drawable.xxx)
to this one:
bitcoin.setImageResource(R.drawable.xxx)

Where do I put "IInAppBillingService.aidl" in a LibGDX project?

I've been trying to get IAP to work with my LibGDX game for Android for over 6 hours. First I tried to use gdx-pay, but sadly the documentation for it is very unclear to me and was therefore not able to get it to work.
Because my games are only for Android (for now) gdx-pay was overkill anyway, so I decided to directly implement Google Play IAP. I found a tutorial that is pretty clear, but sadly it doesn't explain where I should put the IInAppBillingService.aidl file.
I tried putting it in a newly created directory in the Android directory, namely /android/vending/billing, but that doesn't seem to work and the directory also doesn't show when I have my project view on Android.
I also tried creating a new package "andoird.vending.billing" in the java directory where the game package with the AndroidLauncher is in but that doesn't work either.
With both these methods I'm not able to import the class IabHelper in the following tutorial code which is in AndroidLauncher.java located in my game's package:
String base64EncodedPublicKey = "xxx";
// compute your public key and store it in base64EncodedPublicKey
mHelper = new IabHelper(this, base64EncodedPublicKey);
mHelper.startSetup(new IabHelper.OnIabSetupFinishedListener() {
public void onIabSetupFinished(IabResult result) {
if (!result.isSuccess()) {
// Oh noes, there was a problem.
Log.d("IAB", "Problem setting up In-app Billing: " + result);
}
// Hooray, IAB is fully set up!
Log.d("IAB", "Billing Success: " + result);
}
});
Where (and how) am I supposed to put the "IInAppBillingService.aidl" file to be able to import the IabHelper class in my LibGDX project? If you have a clearer tutorial on gdx-pay or on a technique similar to the one I'm using now I would also appreciate it.
Thanks in advance!

Android onCreateOptionsMenu is not displaying

In my android activity, i removed the Action Bar by using this Theme
<style name="Theme.NoTitle" parent="#android:style/Theme.NoTitleBar"></style>
but my problem is “onCreateOptionsMenu” is not display, I tried this method to create
that pls see
private void getOverflowMenu()
{
try
{
ViewConfiguration config = ViewConfiguration.get(Home.this);
Field menuKeyField = ViewConfiguration.class.getDeclaredField("sHasPermanentMenuKey");
if (menuKeyField != null)
{
menuKeyField.setAccessible(true);
menuKeyField.setBoolean(config , false);
}
} catch (Exception e)
{
e.printStackTrace();
}
}
in this “onCreateOptionsMenu” is not displaying. please help me
but it displaying in Samsung
Because: in Samsung mobile has its own hardware menu button, but not in nexus etc
please see the image

finally i got the answer
in my AndroidManifest.xml i just removed this line
android:targetSdkVersion="18"

If you don't have action bar and neither a menu button (on most devices) where do you want to display your menu??
The easiest way is to use PopupMenu. Add a button somewhere in your layout and on the click even add the PopupMenu (Dropdown menu). If you want to use it for devices starting Android 2.1 use a Support Library.
You have HERE the android documentation about PopupMenu.
From SDK Manager you can download and see the support library v7 sample which includes PopupMenuHelper.
Hope it helps. Good Luck!

How to add custom view in android's JellyBean Launcher

I am working on making custom launcher in android. I have referred the code of android's Jellybean launcher. now I want to make some modification in this launcher.
What I want : As we know there are default five work-space screens and I want to add custom view in any one of the workspace screen. My xml file should be inflated in any one of the screen.
I have tried many ways to do it but as the default launcher code is very complex still having no luck to finding out way for it.
There is already app named SOHO in Playstore doing exactly what I want. I have add the screenshot for referencing what i want.
Please help me if anyone of you having any idea to do it.

I've the answer for you. You can do it both in Launcher2 and Launcher3 package from (AOSP). Jellybean is using Launcher2 may be. I personally suggest you to go with Launcher3, it has buit-in way to do so.
Launcher3:
create a class that extends the com.android.launcher3.Launcher class and override the necessary methods like so:
public class MyLauncher extends Launcher {
#Override
protected boolean hasCustomContentToLeft() {
return true;
}
#Override
protected void addCustomContentToLeft() {
View customView = getLayoutInflater().inflate(R.layout.custom, null);
CustomContentCallbacks callbacks = new CustomContentCallbacks() {
#Override
public void onShow() {}
#Override
public void onScrollProgressChanged(float progress) {}
#Override
public void onHide() {}
};
addToCustomContentPage(customView, callbacks, "custom view");
}
}
Here R.layout.custom is the custom view that you wanted.
Then in the manifest file change the launcher activity class from Launcher to MyLauncher. And that's it.
Launcher2:
in Workspace.java create the following method:
public void addCustomView(View child){
CellLayout layout = (CellLayout) getChildAt(0);
layout.addView(child);
}
then in Launcher.java, find the following line:
mWorkspace = (Workspace) mDragLayer.findViewById(R.id.workspace);
then paste the following code somewhere after that line:
View child = LayoutInflater.from(this).inflate(R.layout.custom, null);
mWorkspace.addCustomView(child);

If I remember correctly you just need to implement a standard activity which displays a home launcher. In your Manifest.xml you just need to define it like this:
<activity android:name=".YourLauncher" android:label="#string/launcher_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

you can simply add view in default lanucher use code
wm = (WindowManager) getSystemService("window");
params = new LayoutParams();
params.type = LayoutParams.TYPE_PHONE;
params.format = PixelFormat.RGBA_8888;
params.flags = LayoutParams.FLAG_NOT_TOUCH_MODAL
| LayoutParams.FLAG_NOT_FOCUSABLE;
params.x = 100;
params.y = 100;
params.height = WindowManager.LayoutParams.WRAP_CONTENT;
params.width = WindowManager.LayoutParams.WRAP_CONTENT;
params.gravity = Gravity.LEFT | Gravity.TOP;
wm.addView(view, params);
when you want to remove it
just
wm.removeView(v);
you also need permission
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

Good news, not so good news, bad news. Good new first.
It is possible to do what you want.
Now the not so good news.
You will have to write the launcher application from scratch(aka Home Screen). Yep, that involves doing all those nice and nifty things that the default launcher does(multiple pages, drag and drop, delete/add app icons, etc). Fortunately, its not as difficult as it sounds. Because the default launcher app itself is opensource. Though this code is complete, its not easy to read. A easier place to start would be the SDK
Android-SDK/samples/android-x/Home/
where x is the API level.
They have provided source code for an example home screen and it should give you a good start. With some perseverance and coffee, you should be able to modify the Launcher2 code to add a customized page of your own.
Now the Hard part.
Because a part of your goal is to keep the existing pages same and add a new page, getting this to work for all the flavors of android... HTC sense, Samsung TouchWiz, etc, etc is not a single person workload. They all have different features for the Home screen. Preserving these features and adding a new customized page is a tough task.