CODEWITHSUNDEEP
visual-studiovisual-studio-2015mefvisual-studio-extensionsvsix
cxd213
cxd213

Reputation: 186

MEF Import Exception w/ Visual Studio 2015 Extension

Hoping someone can provide me with some guidance on an issue I'm facing using MEF with my VS2015 extension. I'm attempting to extend the IntelliSense capabilities of VS and followed this tutorial as a basis: https://msdn.microsoft.com/en-us/library/ee372314.aspx

Here is my ICompletionSourceProvider:

[Export(typeof(ICompletionSourceProvider))]
[Name("Test Statement Completion Provider")]
[Order(Before = "default")]
[ContentType("text")]
internal class MyCompletionSourceProvider : ICompletionSourceProvider
{
    [Import]
    internal ITextStructureNavigatorSelectorService NavigatorService { get; set; }

    [Import]
    internal IServiceProvider ServiceProvider { get; set; }

    public ICompletionSource TryCreateCompletionSource(ITextBuffer textBuffer)
    {
        return new MyCompletionSource(this, textBuffer);
    }
}

The strange thing here is that this works fine on my machine (where this code was initially developed on), but fails to work on every other machine I've tried (both in Debug and Release). Breakpoints placed within TryCreateCompletionSource are never hit. I suspected this MEF component was never being exported, so I downloaded the mefx tool as recommend on MSDN and executed it on my generated DLL and received the following:

[Primary Rejection]
[Export] MyVSIX.Source.MyCompletionSourceProvider             (ContractName="Microsoft.VisualStudio.Language.Intellisense.ICompletionSourceProvider")
[Import] MyVSIX.Source.MyCompletionSourceProvider.NavigatorService (ContractName="Microsoft.VisualStudio.Text.Operations.ITextStructureNavigatorSelectorService")
[Exception]   System.ComponentModel.Composition.ImportCardinalityMismatchException: No exports   were found that match the constraint:
ContractName      Microsoft.VisualStudio.Text.Operations.ITextStructureNavigatorSelectorService    
RequiredTypeIdentity      Microsoft.VisualStudio.Text.Operations.ITextStructureNavigatorSelectorService
at System.ComponentModel.Composition.Hosting.ExportProvider.GetExports(ImportDefinition definition, AtomicComposition atomicComposition)
at Microsoft.ComponentModel.Composition.Diagnostics.CompositionInfo.AnalyzeImportDefinition(ExportProvider host, IEnumerable`1 availableParts, ImportDefinition id)    
[Import] MyVSIX.Source.MyCompletionSourceProvider.ServiceProvider (ContractName="System.IServiceProvider")
[Exception] System.ComponentModel.Composition.ImportCardinalityMismatchException: No exports were found that match the constraint: 
ContractName    System.IServiceProvider
RequiredTypeIdentity    System.IServiceProvider
at System.ComponentModel.Composition.Hosting.ExportProvider.GetExports(ImportDefinition definition, AtomicComposition atomicComposition)
at Microsoft.ComponentModel.Composition.Diagnostics.CompositionInfo.AnalyzeImportDefinition(ExportProvider host, IEnumerable`1 availableParts, ImportDefinition id)

If I remove the [Import] statements these are all resolved and things begin working again. From the tutorial though, this seems as though it should just work. This also doesn't explain why it works 100% of the time on my machine and never works on any other machines.

This is my .vsixmanifest file:

<?xml version="1.0" encoding="utf-8"?>
  <PackageManifest Version="2.0.0"  xmlns="http://schemas.microsoft.com/developer/vsx-schema/2011"  xmlns:d="http://schemas.microsoft.com/developer/vsx-schema-design/2011">
    <Metadata>
    <Identity Id="MyVSIX.Company.39048217-955a-4402-84e9-8a24f0730e72" Version="1.0" Language="en-US" Publisher="MyVSIX" />
    <DisplayName>MyVSIX</DisplayName>
    <Description xml:space="preserve"></Description>
    <Icon>Resources\MyVSIX.ico</Icon>
  </Metadata>
  <Installation>
  <InstallationTarget Id="Microsoft.VisualStudio.Community" Version="[14.0]" />
  </Installation>
  <Dependencies>
    <Dependency Id="Microsoft.Framework.NDP" DisplayName="Microsoft .NET Framework" d:Source="Manual" Version="[4.5,)" />
    <Dependency Id="Microsoft.VisualStudio.MPF.14.0" DisplayName="Visual Studio MPF 14.0" d:Source="Installed" Version="[14.0]" />
  </Dependencies>
  <Assets>
    <Asset Type="Microsoft.VisualStudio.VsPackage" d:Source="Project" d:ProjectName="%CurrentProject%" Path="|%CurrentProject%;PkgdefProjectOutputGroup|" />
    <Asset Type="Microsoft.VisualStudio.MefComponent" d:Source="Project" d:ProjectName="%CurrentProject%" Path="|%CurrentProject%|" />
    <Asset Type="Microsoft.VisualStudio.ItemTemplate" Path="Output\ItemTemplates" />
    <Asset Type="Microsoft.VisualStudio.ProjectTemplate" Path="Output\ProjectTemplates" />
  </Assets>
</PackageManifest>

Upvotes: 0

Views: 527

Answers (1)

cxd213
cxd213

Reputation: 186

Figured out why it wasn't working on other machines, but I still cannot understand why it was ever working on my machine. I changed this:

[Import]
internal IServiceProvider ServiceProvider { get; set; }

to this:

[Import(typeof(SVsServiceProvider)]
internal IServiceProvider ServiceProvider { get; set; }

Hope this helps someone in the future - I spent 2 days figuring this out!

Upvotes: 2

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