C# SemanticModel.LookupNamespacesAndTypes方法代码示例

        private IEnumerable<SignatureHelpItem> GetMethodGroupItems(
            InvocationExpressionSyntax invocationExpression,
            SemanticModel semanticModel,
            ISymbolDisplayService symbolDisplayService,
            IAnonymousTypeDisplayService anonymousTypeDisplayService,
            IDocumentationCommentFormattingService documentationCommentFormattingService,
            ISymbol within,
            IEnumerable<IMethodSymbol> methodGroup,
            CancellationToken cancellationToken)
        {
            ITypeSymbol throughType = null;
            if (invocationExpression.Expression is MemberAccessExpressionSyntax)
            {
                var throughExpression = ((MemberAccessExpressionSyntax)invocationExpression.Expression).Expression;
                var throughSymbol = semanticModel.GetSymbolInfo(throughExpression, cancellationToken).GetAnySymbol();

                // if it is via a base expression "base.", we know the "throughType" is the base class but
                // we need to be able to tell between "base.M()" and "new Base().M()".
                // currently, Access check methods do not differentiate between them.
                // so handle "base." primary-expression here by nulling out "throughType"
                if (!(throughExpression is BaseExpressionSyntax))
                {
                    throughType = semanticModel.GetTypeInfo(throughExpression, cancellationToken).Type;
                }

                var includeInstance = !throughExpression.IsKind(SyntaxKind.IdentifierName) ||
                    semanticModel.LookupSymbols(throughExpression.SpanStart, name: throughSymbol.Name).Any(s => !(s is INamedTypeSymbol)) ||
                    (!(throughSymbol is INamespaceOrTypeSymbol) && semanticModel.LookupSymbols(throughExpression.SpanStart, container: throughSymbol.ContainingType).Any(s => !(s is INamedTypeSymbol)));

                var includeStatic = throughSymbol is INamedTypeSymbol ||
                    (throughExpression.IsKind(SyntaxKind.IdentifierName) &&
                    semanticModel.LookupNamespacesAndTypes(throughExpression.SpanStart, name: throughSymbol.Name).Any(t => t.GetSymbolType() == throughType));

                Contract.ThrowIfFalse(includeInstance || includeStatic);
                methodGroup = methodGroup.Where(m => (m.IsStatic && includeStatic) || (!m.IsStatic && includeInstance));
            }
            else if (invocationExpression.Expression is SimpleNameSyntax &&
                invocationExpression.IsInStaticContext())
            {
                methodGroup = methodGroup.Where(m => m.IsStatic);
            }

            var accessibleMethods = methodGroup.Where(m => m.IsAccessibleWithin(within, throughTypeOpt: throughType)).ToList();
            if (accessibleMethods.Count == 0)
            {
                return null;
            }

            var methodSet = accessibleMethods.ToSet();
            accessibleMethods = accessibleMethods.Where(m => !IsHiddenByOtherMethod(m, methodSet)).ToList();

            return accessibleMethods.Select(m =>
                ConvertMethodGroupMethod(m, invocationExpression, semanticModel, symbolDisplayService, anonymousTypeDisplayService, documentationCommentFormattingService, cancellationToken));
        }

        protected static IEnumerable<ISymbol> GetRecommendedNamespaceNameSymbols(
            SemanticModel semanticModel, SyntaxNode declarationSyntax, CancellationToken cancellationToken)
        {
            if (declarationSyntax == null)
            {
                throw new ArgumentNullException(nameof(declarationSyntax));
            }

            var containingNamespaceSymbol = semanticModel.Compilation.GetCompilationNamespace(
                semanticModel.GetEnclosingNamespace(declarationSyntax.SpanStart, cancellationToken));

            var symbols = semanticModel.LookupNamespacesAndTypes(declarationSyntax.SpanStart, containingNamespaceSymbol)
                                       .Where(recommendationSymbol => IsNonIntersectingNamespace(recommendationSymbol, declarationSyntax));

            return symbols;
        }

        // We must verify that the alias actually binds back to the thing it's aliasing.
        // It's possible there's another symbol with the same name as the alias that binds
        // first
        private static bool ValidateAliasForTarget(IAliasSymbol aliasReplacement, SemanticModel semanticModel, ExpressionSyntax node, ISymbol symbol)
        {
            var aliasName = aliasReplacement.Name;

            var boundSymbols = semanticModel.LookupNamespacesAndTypes(node.SpanStart, name: aliasName);

            if (boundSymbols.Length == 1)
            {
                var boundAlias = boundSymbols[0] as IAliasSymbol;
                if (boundAlias != null && aliasReplacement.Target.Equals(symbol))
                {
                    return true;
                }
            }

            return false;
        }

        public static IAliasSymbol GetAliasForSymbol(INamespaceOrTypeSymbol symbol, SyntaxToken token, SemanticModel semanticModel, CancellationToken cancellationToken)
        {
            var originalSemanticModel = semanticModel.GetOriginalSemanticModel();
            if (!originalSemanticModel.SyntaxTree.HasCompilationUnitRoot)
            {
                return null;
            }

            IAliasSymbol aliasSymbol;
            var namespaceId = GetNamespaceIdForAliasSearch(semanticModel, token, cancellationToken);
            if (namespaceId < 0)
            {
                return null;
            }

            if (!AliasSymbolCache.TryGetAliasSymbol(originalSemanticModel, namespaceId, symbol, out aliasSymbol))
            {
                // add cache
                AliasSymbolCache.AddAliasSymbols(originalSemanticModel, namespaceId, semanticModel.LookupNamespacesAndTypes(token.SpanStart).OfType<IAliasSymbol>());

                // retry
                AliasSymbolCache.TryGetAliasSymbol(originalSemanticModel, namespaceId, symbol, out aliasSymbol);
            }

            return aliasSymbol;
        }

        private static IEnumerable<ISymbol> GetSymbols(SyntaxToken token, SemanticModel semanticModel, CancellationToken cancellationToken)
        {
            if (IsCrefStartContext(token))
            {
                return GetUnqualifiedSymbols(token, semanticModel, cancellationToken);
            }
            else if (IsCrefParameterListContext(token))
            {
                return semanticModel.LookupNamespacesAndTypes(token.SpanStart);
            }
            else if (IsCrefQualifiedNameContext(token))
            {
                return GetQualifiedSymbols((QualifiedCrefSyntax)token.Parent, token, semanticModel, cancellationToken);
            }

            return SpecializedCollections.EmptyEnumerable<ISymbol>();
        }