Null pointer exception in OnManipulationCompleted

[schlabo]

When stress-testing the auto complete text box, it is rather easy to produce an internal unhandled exception which then moves to the app's unhandled exception handler.

This exception is thrown in the internal code of the control, and not as a result of a method triggered by me. Is there any chance I can prevent the app from crashing until you can fix the issue?

For the autocomplete suggestions, I'm using a web service (geocoding in my case). The autocomplete text box is initialized similarly to your example app. Here some reference code:

Page constructor:

{
    _autoCompleteProvider = new WebServiceAutoCompleteProvider();
    SearchTextBox.InitSuggestionsProvider(_autoCompleteProvider);
    _autoCompleteProvider.InputChanged += OnAutoCompleteProviderInputChanged;
}

private void OnAutoCompleteProviderInputChanged(object sender, EventArgs e)
{
    _searchGeocodeQuery = new GeocodeQuery { SearchTerm = SearchTextBox.Text };
    // ... async launch
}

Two examples of uncought exceptions:
[Type]:[NullReferenceException]
[ExceptionMessage]:[Object reference not set to an instance of an object.]
[StackTrace]:[
   at Telerik.Windows.Controls.AutoCompleteTextBox.AutoCompleteItem.OnManipulationCompleted(ManipulationCompletedEventArgs e)
   at System.Windows.Controls.Control.OnManipulationCompleted(Control ctrl, EventArgs e)
   at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, Int32 actualArgsTypeIndex, String eventName)]
[InnerException]:[none]

[Type]:[NullReferenceException]
[ExceptionMessage]:[Object reference not set to an instance of an object.]
[StackTrace]:[
   at Telerik.Windows.Controls.AutoCompleteTextBox.AutoCompleteItem.OnClick()
   at Telerik.Windows.Controls.AutoCompleteTextBox.AutoCompleteItem.OnManipulationCompleted(ManipulationCompletedEventArgs e)
   at System.Windows.Controls.Control.OnManipulationCompleted(Control ctrl, EventArgs e)
   at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, Int32 actualArgsTypeIndex, String eventName)]
[InnerException]:[none]

[Deyan]

Hi Andreas,

Thanks for writing and for reporting this.

To be able to handle the case, we need to know how to reproduce the issue on our side.

Is it possible for you to produce a very simple project and share with us the steps we need to take in order for the exception to occur?

To be able to attach your project, you will need to open a new support ticket.

It it's easier for you, you may try to reproduce the issue using our Telerik Examples application and let us know how to do it on our side. We will make sure to debug it.

Thanks for your time.

Regards,
Deyan
Telerik

[Morgan]

I am seeing the same thing, Not sure if its a function of complex types and binding but its definitely causing me some grief.  It didn't happen in previous release this is definitely a new bug.

Pretty sure it has to do with selection from with in the Filter popup, after you enter in some filter data associated with the FilterPath you manipulate the contents of the popup and finally selection is what yields the error, doesn't even get to the SuggestionSelection event.



Morgan Vermef

[Deyan]

Hi Morgan,

As requested earlier in this thread, we will need a sample project that reproduces this issue to be able to investigate it and see what causes the bug. Is it possible for you to send us such project? To make things easier for you, it will suffice if you manage to reproduce the issue within our Telerik Examples project with the AutoCompleteBox demos. We have the source here and will be able to debug the case.

Thanks for your time.

Regards,
Deyan
Telerik

[Morgan]

saw latest internal build downloading and seeing if problem still exists...

update: early but I would say this has been fixed...

[Deyan]

Hello Morgan,

This issue should be addressed in our latest internal build.

Make sure you correctly update your references and let us know if you think the issue persists.

We will close this thread for now. Do not hesitate to reopen it if needed.

Regards,
Deyan
Telerik