private bool TryGetProviderContext <T>(IVsReferenceManagerUser manager, out T context) where T : IVsReferenceProviderContext
{
ThreadHelper.ThrowIfNotOnUIThread();
T?value = manager.GetProviderContexts().OfType <T>().FirstOrDefault();
if (value is not null)
{
context = value;
return(true);
}
context = default !;
/// <summary>
/// Removes the given references from the project.
/// </summary>
/// <param name="references">The references to remove.</param>
/// <returns>A task.</returns>
public async Task RemoveAsync(params Reference[] references)
{
await ThreadHelper.JoinableTaskFactory.SwitchToMainThreadAsync();
// There doesn't seem to be an easy way to actually remove references from a project.
// There is no direct way to map an `IVsReference` instance to the provider that handles
// that type of reference, and the `IVsReferenceProviderContext` has no way to remove a
// reference from its `References` property. What we do here might seem like a bit of a hack,
// but it appears to work fine.
//
// We start by creating a mapping from an `IVsReference` type to the corresponding provider
// context by getting each provider context to create a reference object. The provider
// context just creates a new object and doesn't seem to do anything with it, so this
// shouldn't have any side effects. This gives us a way to get the provider context
// that an `IVsReference` object is handled by.
//
// But, the provider contexts from the manager contain all of the existing references with no
// way to remove reference objects from them, so we can't pass those contexts to the manager
// when calling `ChangeReferences()` because that will remove all existing references!
// What we will do is create an instance of our own implementation of a provider context
// so that the provider context will only contain the references that we want to remove.
Dictionary <Type, RemovingReferenceProviderContext> contextsByReferenceType = new();
IVsReferenceManagerUser manager = GetManager();
foreach (IVsReferenceProviderContext context in manager.GetProviderContexts().OfType <IVsReferenceProviderContext>())
{
contextsByReferenceType[context.CreateReference().GetType()] = new RemovingReferenceProviderContext(context.ProviderGuid);
}
foreach (Reference reference in references)
{
if (contextsByReferenceType.TryGetValue(reference.VsReference.GetType(), out RemovingReferenceProviderContext context))
{
context.AddReference(reference.VsReference);
}
}
foreach (IVsReferenceProviderContext context in contextsByReferenceType.Values.Where((x) => x.HasReferences))
{
manager.ChangeReferences((uint)__VSREFERENCECHANGEOPERATION.VSREFERENCECHANGEOPERATION_REMOVE, context);
}
}