xamarin/Xamarin.Forms

[Bug] XAML compilation faills with compiled bindings on UWP

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#6,547 opened on Jun 16, 2019

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3.5.0a/Xaml </>e/5 :clock5:help wantedi/regressionp/UWPt/bug :bug:up-for-grabs

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Description

Description

UWP project fails to build if it contains any kind of Xamarin.Forms compiled bindings. Build output:

CompiledColorSelectorPage.xaml : error : Value cannot be null.
CompiledColorSelectorPage.xaml : error : Parameter name: type

Possibly related to #5416

Affected Setups:

Bug appears only if .xaml is in UWP project or a shared project linked to one. Data bindings demos and other projects with bindings as a part of .NET Standard library aren't affected. Android projects aren't affected.

Steps to Reproduce

Create a blank Xamarin.Forms + UWP project, move Xamarin.Forms files to UWP project, add a page with compiled bindings, build.

Basic Information

  • Versions with issue: 3.5.0.129452, 4.0.0.497661, 4.1.0.496342-pre2
  • Last known good version: 3.4.0.1039999
  • IDE: VS Community 2017 and 2019
  • Platform Target Frameworks:
    • UWP: 16299, 17763

Reproduction Link

CompiledBindings.zip — a blank project with a page from data binding demos.

Contributor guide

Research direction
Investigate the XAML compiled bindings code for UWP, focusing on the error 'Value cannot be null. Parameter name: type'. Trace the compilation path and identify where null type is passed. Check if issue is related to #5416.
Tech stack
csharp
Domain
desktopbuild system
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
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Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Git
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70