The DetailedList() method in Toga version 0.3.1 is working properly. After upgrading to version 0.4.2, there was an issue when calling the on_select parameter on the Android side, but everything is working fine on the Windows side.

[jlij]

--------- beginning of crash
E/AndroidRuntime: FATAL EXCEPTION: main
E/AndroidRuntime: Process: vip.eicp.patrol, PID: 31258
E/AndroidRuntime: com.chaquo.python.PyException: TypeError: patrol.on_select_car() got an unexpected keyword argument 'row'
E/AndroidRuntime: at .toga.handlers._handler(handlers.py:66)
E/AndroidRuntime: at .toga_android.widgets.detailedlist.onClick(detailedlist.py:34)
E/AndroidRuntime: at .chaquopy_java.call(chaquopy_java.pyx:354)
E/AndroidRuntime: at .chaquopy_java.Java_com_chaquo_python_PyObject_callAttrThrowsNative(chaquopy_java.pyx:326)
E/AndroidRuntime: at com.chaquo.python.PyObject.callAttrThrowsNative(Native Method)
E/AndroidRuntime: at com.chaquo.python.PyObject.callAttrThrows(PyObject.java:232)
E/AndroidRuntime: at com.chaquo.python.PyInvocationHandler.invoke(PyInvocationHandler.java:31)
E/AndroidRuntime: at java.lang.reflect.Proxy.invoke(Proxy.java:913)
E/AndroidRuntime: at $Proxy8.onClick(Unknown Source)
E/AndroidRuntime: at android.view.View.performClick(View.java:6291)
E/AndroidRuntime: at android.view.View$PerformClick.run(View.java:24931)
E/AndroidRuntime: at android.os.Handler.handleCallback(Handler.java:808)
E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:101)
E/AndroidRuntime: at android.os.Looper.loop(Looper.java:166)
E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:7529)
E/AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime: at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:245)
E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:921)
I/Process : Sending signal. PID: 31258 SIG: 9

[freakboy3742]

When reporting an error, a critical part of the report is telling us what you did to generate the error. Without sample code, it's almost impossible to resolve any issue.

In this case, the error suggests that you haven't adapted to one of the backwards incompatible changes in the 0.4 release - specifically, the change in prototype for the on_select handler no longer accepts a row argument. This is specifically called out in the Backwards incompatibility notes for the 0.4.0 release.

[freakboy3742]

You are not running that code. The handler in your stack trace is patrol.on_select_car(). That is not the name of the on_select handler in that example app.

[jlij]

--------- beginning of crash
E/AndroidRuntime: FATAL EXCEPTION: main
E/AndroidRuntime: Process: vip.eicp.patrol, PID: 17685
E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{vip.eicp.patrol/org.beeware.android.MainActivity}: com.chaquo.python.PyException: TypeError: DetailedList.init() got an unexpected keyword argument 'missing_value'
E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3303)
E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3411)
E/AndroidRuntime: at android.app.ActivityThread.-wrap12(Unknown Source:0)
E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1994)
E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:108)
E/AndroidRuntime: at android.os.Looper.loop(Looper.java:166)
E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:7529)
E/AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime: at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:245)
E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:921)
E/AndroidRuntime: Caused by: com.chaquo.python.PyException: TypeError: DetailedList.init() got an unexpected keyword argument 'missing_value'
E/AndroidRuntime: at .patrol.app.startup(app.py:105)
E/AndroidRuntime: at .toga_android.app.create(app.py:175)
E/AndroidRuntime: at .toga_android.app.main_loop(app.py:186)
E/AndroidRuntime: at .toga.app.main_loop(app.py:517)
E/AndroidRuntime: at .main.(main.py:4)
E/AndroidRuntime: at .runpy._run_code(:88)
E/AndroidRuntime: at .runpy._run_module_code(:98)
E/AndroidRuntime: at .runpy.run_module(:226)
E/AndroidRuntime: at .chaquopy_java.call(chaquopy_java.pyx:354)
E/AndroidRuntime: at .chaquopy_java.Java_com_chaquo_python_PyObject_callAttrThrowsNative(chaquopy_java.pyx:326)
E/AndroidRuntime: at com.chaquo.python.PyObject.callAttrThrowsNative(Native Method)
E/AndroidRuntime: at com.chaquo.python.PyObject.callAttrThrows(PyObject.java:232)
E/AndroidRuntime: at com.chaquo.python.PyObject.callAttr(PyObject.java:221)
E/AndroidRuntime: at org.beeware.android.MainActivity.onCreate(MainActivity.java:85)
E/AndroidRuntime: at android.app.Activity.performCreate(Activity.java:7383)
E/AndroidRuntime: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1218)
E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3256)
E/AndroidRuntime: ... 9 more
I/Process : Sending signal. PID: 17685 SIG: 9

[freakboy3742]

That is a different error, and still doesn't correspond to the example app you've referenced.

And, again, the error message is telling you what is wrong - DetailedList.__init__() got an unexpected keyword argument 'missing_value'. This is a valid argument in 0.4.2, so if you're getting this message, it means you're not using Toga 0.4.2 when the code is running on Android. This is likely because your dependencies haven't been updated.

[jlij]

Sorry, after carefully reading the example you provided, we found that an important parameter * * kwargs is missing. After adding it, it worked fine. Thank you very much for your reply.