Native Android crash when resettin ItemSelected property

[Matteo Comi]

Hello,

I created a page with a simple form, having some entries and some SfComboBox as user input. Entries values and SfComboBox SelectedItem properties are binded to a ViewModel in MVVM way.

I added a "Reset" button that should clear the inputs: strings are correctly cleared, but if I choose an item in one of my SfComboBox elements the application crashes and no exception is raised by Visual Studio.

Here's an example of the XAML code:

<combobox:SfComboBox x:Name="ComboboxTipiDomande" Margin="0" DataSource="{Binding ListaTipiDomande}" IsEnabled="{Binding IsEnabled}" SelectedItem="{Binding ItemSelectedTipiDomande, Mode=TwoWay}" Style="{StaticResource ComboBoxDetailStyle}" Watermark="{i18n:Translate Text=StringTipoDomanda}" />

<combobox:SfComboBox Margin="0" DataSource="{Binding ListaNumeroNote}" IsEnabled="{Binding IsEnabled}" SelectedItem="{Binding ItemSelectedNumeroNote, Mode=TwoWay}" Style="{StaticResource ComboBoxDetailStyle}" Watermark="{i18n:Translate Text=StringNumeroNote}" />

Here's the reset command:

private void ExecuteResetCommand()
{
     IsEnabled = true;

     Testo = string.Empty;

     ItemSelectedTipiDomande = null;
     Valori = string.Empty;
     IsSelectedAttributo = false;
     Requisito = string.Empty;

     ItemSelectedDomande = null;

     ItemSelectedNumeroNote = ListaNumeroNote.FirstOrDefault();
     PlaceholderNote = string.Empty;
}

If I set the SelectedItem to the first item of a collection of strings (for example the italic line of code), no error occurs. If I set the SelectedItem to null for a collection of objects (for example the bold line aof code), then the application crashes. Here's an exceprt of the stacktrace:

Native Crash Reporting
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries
used by your application.

Basic Fault Adddress Reporting
Memory around native instruction pointer (0x72cb8ff678):0x72cb8ff668  00 1c 40 b9 c0 03 5f d6 fd 7b bf a9 fd 03 00 91  ..@..._..{......
0x72cb8ff678  08 20 40 b9 a8 00 c8 37 88 01 e0 37 00 00 40 f9  . @....7...7..@.
0x72cb8ff688  fd 7b c1 a8 c0 03 5f d6 60 08 00 b0 01 0a 00 f0  .{...._.`.......
0x72cb8ff698  03 0a 00 f0 00 24 06 91 21 80 08 91 63 8c 0a 91  .....$..!...c...

No native Android stacktrace (see debuggerd output).
Managed Stacktrace:
06-13 18:07:07.461 E/mono-rt (25057): /proc/self/maps:
06-13 18:07:07.461 E/mono-rt (25057): 12c00000-52c00000 rw-p 00000000 00:01 770                                /dev/ashmem/dalvik-main space (region space) (deleted)
06-13 18:07:07.461 E/mono-rt (25057): 6f309000-6f5b1000 rw-p 00000000 103:09 57577                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 6f5b1000-6f6b7000 rw-p 00000000 103:09 57579                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 6f6b7000-6f701000 rw-p 00000000 103:09 57581                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 6f701000-6f737000 rw-p 00000000 103:09 57582                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 6f737000-6f73b000 rw-p 00000000 103:09 57584                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 6f73b000-6f77e000 rw-p 00000000 103:09 57587                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 6f77e000-6f7b9000 rw-p 00000000 103:09 57589                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 6f7b9000-6ffa6000 rw-p 00000000 103:09 57591                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 6ffa6000-70032000 rw-p 00000000 103:09 57596                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 70032000-7003b000 rw-p 00000000 103:09 57598                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 7003b000-70044000 rw-p 00000000 103:09 57600                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 70044000-70068000 rw-p 00000000 103:09 57602                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 70068000-70090000 rw-p 00000000 103:09 57604                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 70090000-70091000 rw-p 00000000 103:09 57606                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 70091000-70094000 rw-p 00000000 103:09 57607                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.461 E/mono-rt (25057): 70094000-7011f000 rw-p 00000000 103:09 57610                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.462 E/mono-rt (25057): 7011f000-70146000 rw-p 00000000 103:09 57612                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.462 E/mono-rt (25057): 70146000-7017f000 rw-p 00000000 103:09 57614                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.462 E/mono-rt (25057): 7017f000-70181000 rw-p 00000000 103:09 57617                             /data/dalvik-cache/arm64/system@[e-mail]
06-13 18:07:07.462 E/mono-rt (25057): 70181000-70182000 rw-p 00000000 103:09 57619                             /data/dalvik-cache/arm64/system@[e-mail]

06-13 18:07:07.462 E/mono-rt (25057): 70182000-70188000 rw-p 00000000 103:09 57621                             /data/dalvik-cache/arm64/system@[e-mail]

...

06-13 18:07:07.466 F/libc    (25057): Fatal signal 11 (SIGSEGV), code 1, fault addr 0x20 in tid 25057 (ca.AuditManager)

How can I investigate and solve the problem?

Thanks in advance,

Matteo

[Rabhia Beham Kathar Mideenar]

Hi Matteo,

Greetings from Syncfusion.

We have checked the code snippet and have created a simple sample with the SfComboBox and unfortunately we are unable to reproduce the issue. Please have the sample with which we have checked the issue.

Sample Link: http://www.syncfusion.com/downloads/support/directtrac/general/ze/ComboBox_145249478436873

Please check with the sample and if issue still persists from your side modify the sample with the issue reproducing sample which will be helpful for us to analyse further and provide an appropriate solution.

Regards,
Rabhia beham K.