Bug 25648 - On WinPhone 8.1, a second call to ConvertPageToUIElement(this) throws InvalidOperationException
Summary: On WinPhone 8.1, a second call to ConvertPageToUIElement(this) throws Invalid...
Alias: None
Product: Forms
Classification: Xamarin
Component: Forms ()
Version: 1.2.3
Hardware: PC Windows
: Normal normal
Target Milestone: ---
Assignee: Jason Smith [MSFT]
Depends on:
Reported: 2014-12-29 23:05 UTC by Jon Goldberger [MSFT]
Modified: 2015-01-16 22:05 UTC (History)
4 users (show)

Is this bug a regression?: ---
Last known good build:

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Description Jon Goldberger [MSFT] 2014-12-29 23:05:39 UTC
## Description

Running a Xamarin.Forms project where the WinPhone app project calls ConvertPageToUIElement(this) more than once results in an InvalidOperationException. Running the same code on WinPhone 8.0 works fine. 

## Steps to reproduce:

1. Download the following sample Forms project:

2. Open in Visual Studio.

3. Set the Winphone project as the startup project.

4. Deploy it to a WinPhone 8.1 emulator.

5. Enter any credentials and click the Login button.

Expected result: The Master/Detail page will be shown.

Actual result: InvalidOperationException is thrown. Stack trace:

System.InvalidOperationException was unhandled by user code
>  HResult=-2146233079
>  Message=Can not create more than one Application instance.
>  Source=Xamarin.Forms.Core
>  StackTrace:
>       at Xamarin.Forms.Application.set_Current(Application value)
>       at Xamarin.Forms.Application..ctor()
>       at Xamarin.Forms.Forms.DefaultApplication..ctor(Page mainPage)
>       at Xamarin.Forms.Forms.ConvertPageToUIElement(Page page, PhoneApplicationPage applicationPage)
>       at LoginPattern.WinPhone.MainPage.ShowMainPage()
>       at LoginPattern.LoginPage.<>c__DisplayClassc.<.ctor>b__8(Object sender, EventArgs e)
>       at Xamarin.Forms.Button.Xamarin.Forms.IButtonController.SendClicked()
>       at Xamarin.Forms.Platform.WinPhone.ButtonRenderer.HandleButtonClick(Object sender, RoutedEventArgs e)
>       at System.Windows.Controls.Primitives.ButtonBase.OnClick()
>       at System.Windows.Controls.Button.OnClick()
>       at System.Windows.Controls.Primitives.ButtonBase.<OnMouseLeftButtonUp>b__9()

## Notes

I tried avoiding the second call to ConvertPageToUIElement(this) by pushing the main page to the navigation stack in the forms PCL project instead of calling the ShowMainPage() method of the ILoginManager interface that is implemented in the WinPhone project. This did avoid the exception, but of course the page was not loaded properly, i.e. only the Detail page is shown with no button to get to the Master Page. However it does make it seem that it is the ConvertPageToUIElement(this) method that is trying to initialize the application again, resulting in the exception.
Comment 1 Jon Goldberger [MSFT] 2014-12-29 23:07:29 UTC
Additional note:

The sample app runs fine on WinPhone 8.0
Comment 2 Jon Goldberger [MSFT] 2014-12-29 23:19:42 UTC
Tested using Xamarin.Forms 1.2.2 (version in sample project) and the latest pre-release Same results in both cases.
Comment 3 Danish Akhtar 2015-01-05 08:48:44 UTC
I have checked this issue and with the help of steps mentioned in bug description I am able to reproduce this behavior.

When I enter the credentials (Username: test/ Password: test) and click the Login button I observed that I am getting following exception:

>System.InvalidOperationException was unhandled by user code HResult=-2146233079

Screencast:- http://www.screencast.com/t/Jf968ii7iLc

Exception detail: https://gist.github.com/RamChBachkheti/23f9e5a35675f3972633
Debug logs: https://gist.github.com/RamChBachkheti/efe5af37a9760f74060e
IDE logs: https://gist.github.com/RamChBachkheti/921341ac6d1dce1468b9

Additional Info: I am not getting this behavior with Xamarin.Forms:

Environment Info:

Microsoft Visual Studio Professional 2013
Version 12.0.30723.00 Update 3
Microsoft .NET Framework
Version 4.5.51641

Installed Version: Professional

LightSwitch for Visual Studio 2013   06177-004-0447006-02641
Microsoft LightSwitch for Visual Studio 2013

Team Explorer for Visual Studio 2013   06177-004-0447006-02641
Microsoft Team Explorer for Visual Studio 2013

Visual Basic 2013   06177-004-0447006-02641
Microsoft Visual Basic 2013

Visual C# 2013   06177-004-0447006-02641
Microsoft Visual C# 2013

Visual C++ 2013   06177-004-0447006-02641
Microsoft Visual C++ 2013

Visual F# 2013   06177-004-0447006-02641
Microsoft Visual F# 2013

Visual Studio 2013 Code Analysis Spell Checker   06177-004-0447006-02641
Microsoft® Visual Studio® 2013 Code Analysis Spell Checker

Portions of International CorrectSpell™ spelling correction system © 1993 by Lernout & Hauspie Speech Products N.V. All rights reserved.

The American Heritage® Dictionary of the English Language, Third Edition Copyright © 1992 Houghton Mifflin Company. Electronic version licensed from Lernout & Hauspie Speech Products N.V. All rights reserved.

Windows Phone SDK 8.0 - ENU   06177-004-0447006-02641
Windows Phone SDK 8.0 - ENU

Application Insights Tools for Visual Studio Package   1.0
Application Insights Tools for Visual Studio

ASP.NET and Web Tools   12.3.50717.0
Microsoft Web Developer Tools contains the following components:
Support for creating and opening ASP.NET web projects
Browser Link: A communication channel between Visual Studio and browsers
Editor extensions for HTML, CSS, and JavaScript
Page Inspector: Inspection tool for ASP.NET web projects
Scaffolding: A framework for building and running code generators
Server Explorer extensions for Microsoft Azure Websites
Web publishing: Extensions for publishing ASP.NET web projects to hosting providers, on-premises servers, or Microsoft Azure

ASP.NET Web Frameworks and Tools 2012.2   4.1.21001.0
For additional information, visit http://go.microsoft.com/fwlink/?LinkID=309563

ASP.NET Web Frameworks and Tools 2013   5.2.20703.0
For additional information, visit http://www.asp.net/

Common Azure Tools   1.2
Provides common services for use by Azure Mobile Services and Microsoft Azure Tools.

Microsoft Advertising SDK for Windows Phone   
Microsoft Advertising SDK for Windows Phone

Microsoft Azure Mobile Services Tools   1.2
Microsoft Azure Mobile Services Tools

NuGet Package Manager   2.8.50926.663
NuGet Package Manager in Visual Studio. For more information about NuGet, visit http://docs.nuget.org/.

Office Developer Tools for Visual Studio 2013 ENU   12.0.30626
Microsoft Office Developer Tools for Visual Studio 2013 ENU

PowerShell Tools   1.2
Provides file classification services using PowerShell

PreEmptive Analytics Visualizer   1.2
Microsoft Visual Studio extension to visualize aggregated summaries from the PreEmptive Analytics product.

SQL Server Data Tools   12.0.30919.1
Microsoft SQL Server Data Tools

Windows Phone 8.1 SDK Integration   1.0
This package integrates the tools for the Windows Phone 8.1 SDK into the menus and controls of Visual Studio.

Workflow Manager Tools 1.0   1.0
This package contains the necessary Visual Studio integration components for Workflow Manager.

Xamarin (10cfd178d55287f09c85f5a1e604dfe20889a40f)
Visual Studio extension to enable development for Xamarin.iOS and Xamarin.Android.

Xamarin.Android (ba9bbbdd44cfdc4bf485e8885bd2ad24fba525f7)
Visual Studio plugin to enable development for Xamarin.Android.

Xamarin.iOS (840a925103a0bf4a856507f13d5eaee3c1579c2f)
Visual Studio extension to enable development for Xamarin.iOS.

Xamarin.iOS Unified Migration   1.0
Automated migration for Xamarin iOS Classic projects to Unified
Comment 4 Jason Smith [MSFT] 2015-01-16 22:05:32 UTC
Should be fixed in 1.3.2-pre1