Android Question hi,please help me about this error. thanks

[Keivan]

** Activity (main) Resume **
java.lang.NoClassDefFoundError: Failed resolution of: Landroidx/lifecycle/ViewTreeLifecycleOwner;
at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2970)
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:518)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:282)
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2189)
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2100)
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:2002)
at androidx.fragment.app.FragmentManager$5.run(FragmentManager.java:524)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6138)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:893)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:783)
Caused by: java.lang.ClassNotFoundException: Didn't find class "androidx.lifecycle.ViewTreeLifecycleOwner" on path: DexPathList[[zip file "/data/app/com.toefl.plus.litner.frd-2/base.apk"],nativeLibraryDirectories=[/data/app/com.toefl.plus.litner.frd-2/lib/x86, /data/app/com.toefl.plus.litner.frd-2/base.apk!/lib/x86, /system/lib, /vendor/lib, /data/downloads, /data/priv-downloads]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.java:380)
at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
... 14 more

 

[DonManfred]

what are you trying to do? Post your code. Best is to upload a small project showing the problem.

Looks like you are using an old (and outdated/deprecated) SDK?

What is the b4a Version you are using?

Please post the compilationwindow-output.

You need to compile against AndroidX but i fear you are not.

 

[Keivan]

what are you trying to do? Post your code. Best is to upload a small project showing the problem.

Looks like you are using an old (and outdated/deprecated) SDK?

What is the b4a Version you are using?

Please post the compilationwindow-output.

You need to compile against AndroidX but i fear you are not.

Thanks bro.. I use last version B4A and SDK.
but i replace fragment -1.3.6 with fragment-1.2.5 and get this error.
(tow of libs use different fragment )

androidx.fragment\:fragment=1.3.6

 

[Erel]

Which libraries are you using?

 

[Keivan]

Which libraries are you using?

I use two Persian libraries.
"Hitex_persiancalandarview" and"poolakey"
I think it doesn't matter, because each one runs with different versions of the fragment.
thanks Erel.

 

[Erel]

I guess that one of them isn't compatible with the current Android SDK version.

 

[Keivan]

Can the error be removed using the code?
(Sorry for my bad English)

 

[Erel]

Impossible to say.