Bug 59884 (PickerOneWayToSourceBinding) - Picker does not Support OneWayToSource
Summary: Picker does not Support OneWayToSource
Alias: PickerOneWayToSourceBinding
Product: Forms
Classification: Xamarin
Component: Forms ()
Version: 2.4.0
Hardware: PC Windows
: --- normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2017-10-02 07:37 UTC by Armin Fallah
Modified: 2017-10-04 23:05 UTC (History)
2 users (show)

Tags: Picker, OneWayToSource, Binding, ac
Is this bug a regression?: ---
Last known good build:

A simple example (269.81 KB, application/zip)
2017-10-04 20:42 UTC, Armin Fallah

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Description Armin Fallah 2017-10-02 07:37:21 UTC
It appears that Xamarin.Forms.Picker control's SelectedIndex property does not support OneWayToSource binding mode throwing the following exception

Unhandled Exception:

System.Reflection.TargetInvocationException: <Timeout exceeded getting exception details> occurred
Comment 1 Paul DiPietro [MSFT] 2017-10-03 19:36:40 UTC
Can you upload a reproduction project to help us investigate more quickly? Are you experiencing this as a regression in 2.4.0 or is this an issue that has existed prior?
Comment 2 Armin Fallah 2017-10-04 20:42:43 UTC
Created attachment 25113 [details]
A simple example
Comment 3 Armin Fallah 2017-10-04 20:54:33 UTC
Thank you for answer Mr.DiPietro,
I attached a simple example that shows how the bug occurs. There is an explanation commented in MainPage.xaml in the PCL.
Regarding your concern that 2.4.0 might have caused this, unfortunately I did not use OneWayToSource binding mode for Picker's SelectedIndex prior to 2.4.0 so i can't be sure but if I had to guess, I would say that since this is a special case rarely used by the community, no one has noticed it up until now.
Ofcourse I only take it upon myself to report any/all bugs since Xamarin.Forms is one my favourite technologies and i hope to see it complete and as bug-free as possible.
My thanks to you and the Xamarin's team at microsoft ! :)
Comment 4 Paul DiPietro [MSFT] 2017-10-04 23:05:15 UTC
Thank you for the reproduction; I'll set this to confirmed for now until we can look at this further.