protected override void AddVirtuals (List<IMember> alreadyInserted, CompletionDataWrapper col, string modifiers, IType curType, int declarationBegin)
		{
			base.AddVirtuals (alreadyInserted, col, modifiers, curType, declarationBegin);
			foreach (var member in GetProtocolMembers (curType)) {
				if (alreadyInserted.Contains (member))
					continue;
				if (BaseExportCodeGenerator.IsImplemented (curType, member))
					continue;
				alreadyInserted.Add (member);
				var data = new ProtocolCompletionData (this, declarationBegin, member);
				col.Add (data);
			}
		}

		void AddContextCompletion(CompletionDataWrapper wrapper, CSharpResolver state, AstNode node, CompilationUnit unit)
		{
			if (state != null && !(node is AstType)) {
				foreach (var variable in state.LocalVariables) {
					if (variable.Region.IsInside(location.Line, location.Column - 1)) {
						continue;
					}
					wrapper.AddVariable(variable);
				}
			}
			
			if (currentMember is IUnresolvedParameterizedMember && !(node is AstType)) {
				var param = (IParameterizedMember)currentMember.CreateResolved(ctx);
				foreach (var p in param.Parameters) {
					wrapper.AddVariable(p);
				}
			}
			
			if (currentMember is IUnresolvedMethod) {
				var method = (IUnresolvedMethod)currentMember;
				foreach (var p in method.TypeParameters) {
					wrapper.AddTypeParameter(p);
				}
			}
			
			Func<IType, IType> typePred = null;
			if (IsAttributeContext(node)) {
				var attribute = Compilation.FindType(KnownTypeCode.Attribute);
				typePred = t => {
					return t.GetAllBaseTypeDefinitions().Any(bt => bt.Equals(attribute)) ? t : null;
				};
			}
			AddTypesAndNamespaces(wrapper, state, node, typePred);
			
			wrapper.Result.Add(factory.CreateLiteralCompletionData("global"));
			
			if (!(node is AstType)) {
				if (currentMember != null || node is Expression) {
					AddKeywords(wrapper, statementStartKeywords);
					AddKeywords(wrapper, expressionLevelKeywords);
					if (node is TypeDeclaration)
						AddKeywords(wrapper, typeLevelKeywords);
				} else if (currentType != null) {
					AddKeywords(wrapper, typeLevelKeywords);
				} else {
					AddKeywords(wrapper, globalLevelKeywords);
				}
				var prop = currentMember as IUnresolvedProperty;
				if (prop != null && prop.Setter != null && prop.Setter.Region.IsInside(location)) {
					wrapper.AddCustom("value");
				} 
				if (currentMember is IUnresolvedEvent) {
					wrapper.AddCustom("value");
				} 
				
				if (IsInSwitchContext(node)) {
					wrapper.AddCustom("case"); 
				}
			} else {
				if (((AstType)node).Parent is ParameterDeclaration) {
					AddKeywords(wrapper, parameterTypePredecessorKeywords);
				}
			}

			AddKeywords(wrapper, primitiveTypesKeywords);
			if (currentMember != null) {
				wrapper.AddCustom("var");
			} 
			wrapper.Result.AddRange(factory.CreateCodeTemplateCompletionData());
			
			if (node != null && node.Role == Roles.Argument) {
				var resolved = ResolveExpression(node.Parent, unit);
				var invokeResult = resolved != null ? resolved.Item1 as CSharpInvocationResolveResult : null;
				if (invokeResult != null) {
					int argNum = 0;
					foreach (var arg in node.Parent.Children.Where (c => c.Role == Roles.Argument)) {
						if (arg == node) {
							break;
						}
						argNum++;
					}
					var param = argNum < invokeResult.Member.Parameters.Count ? invokeResult.Member.Parameters [argNum] : null;
					if (param != null && param.Type.Kind == TypeKind.Enum) {
						AddEnumMembers(wrapper, param.Type, state);
					}
				}
			}
			
			if (node is Expression) {
				var astResolver = new CSharpAstResolver(state, unit, CSharpParsedFile);
				foreach (var type in CreateFieldAction.GetValidTypes(astResolver, (Expression)node)) {
					if (type.Kind == TypeKind.Enum) {
						AddEnumMembers(wrapper, type, state);
					} else if (type.Kind == TypeKind.Delegate) {
						AddDelegateHandlers(wrapper, type, true, true);
						AutoSelect = false;
						AutoCompleteEmptyMatch = false;
					}
				}
			}
//.........这里部分代码省略.........

		IEnumerable<ICompletionData> CreateCaseCompletionData(TextLocation location)
		{
			var unit = ParseStub("a: break;");
			if (unit == null) {
				return null;
			}
			var s = unit.GetNodeAt<SwitchStatement>(location);
			if (s == null) {
				return null;
			}

			var offset = document.GetOffset(s.Expression.StartLocation);
			var expr = GetExpressionAt(offset);
			if (expr == null) {
				return null;
			}

			var resolveResult = ResolveExpression(expr);
			if (resolveResult == null || resolveResult.Result.Type.Kind != TypeKind.Enum) { 
				return null;
			}
			var wrapper = new CompletionDataWrapper(this);
			AddEnumMembers(wrapper, resolveResult.Result.Type, resolveResult.Resolver);
			AutoCompleteEmptyMatch = false;
			return wrapper.Result;
		}

		IEnumerable<ICompletionData> CreateCompletionData(TextLocation location, ResolveResult resolveResult, AstNode resolvedNode, CSharpResolver state, Func<IType, IType> typePred = null)
		{
			if (resolveResult == null /*			|| resolveResult.IsError*/) {
				return null;
			}

			var lookup = new MemberLookup(
				ctx.CurrentTypeDefinition,
				Compilation.MainAssembly
			);

			if (resolveResult is NamespaceResolveResult) {
				var nr = (NamespaceResolveResult)resolveResult;
				var namespaceContents = new CompletionDataWrapper(this);

				foreach (var cl in nr.Namespace.Types) {
					if (!lookup.IsAccessible(cl, false))
						continue;
					IType addType = typePred != null ? typePred(cl) : cl;
					if (addType != null)
						namespaceContents.AddType(addType, false);
				}

				foreach (var ns in nr.Namespace.ChildNamespaces) {
					namespaceContents.AddNamespace(lookup, ns);
				}
				return namespaceContents.Result;
			}
			IType type = resolveResult.Type;

			if (type.Namespace == "System" && type.Name == "Void")
				return null;

			if (resolvedNode.Parent is PointerReferenceExpression && (type is PointerType)) {
				resolveResult = new OperatorResolveResult(((PointerType)type).ElementType, System.Linq.Expressions.ExpressionType.Extension, resolveResult);
			}

			//var typeDef = resolveResult.Type.GetDefinition();
			var result = new CompletionDataWrapper(this);
			bool includeStaticMembers = false;

			if (resolveResult is LocalResolveResult) {
				if (resolvedNode is IdentifierExpression) {
					var mrr = (LocalResolveResult)resolveResult;
					includeStaticMembers = mrr.Variable.Name == mrr.Type.Name;
				}
			}
			if (resolveResult is TypeResolveResult && type.Kind == TypeKind.Enum) {
				foreach (var field in type.GetFields ()) {
					if (!lookup.IsAccessible(field, false))
						continue;
					result.AddMember(field);
				}
				return result.Result;
			}

			bool isProtectedAllowed = resolveResult is ThisResolveResult ? true : lookup.IsProtectedAccessAllowed(type);
			bool skipNonStaticMembers = (resolveResult is TypeResolveResult);

			if (resolveResult is MemberResolveResult && resolvedNode is IdentifierExpression) {
				var mrr = (MemberResolveResult)resolveResult;
				includeStaticMembers = mrr.Member.Name == mrr.Type.Name;

				TypeResolveResult trr;
				if (state.IsVariableReferenceWithSameType(
					resolveResult,
					((IdentifierExpression)resolvedNode).Identifier,
					out trr
				)) {
					if (currentMember != null && mrr.Member.IsStatic ^ currentMember.IsStatic) {
						skipNonStaticMembers = true;

						if (trr.Type.Kind == TypeKind.Enum) {
							foreach (var field in trr.Type.GetFields ()) {
								if (lookup.IsAccessible(field, false))
									result.AddMember(field);
							}
							return result.Result;
						}
					}
				}
				// ADD Aliases
				var scope = ctx.CurrentUsingScope;

				for (var n = scope; n != null; n = n.Parent) {
					foreach (var pair in n.UsingAliases) {
						if (pair.Key == mrr.Member.Name) {
							foreach (var r in CreateCompletionData (location, pair.Value, resolvedNode, state)) {
								if (r is IEntityCompletionData && ((IEntityCompletionData)r).Entity is IMember) {
									result.AddMember((IMember)((IEntityCompletionData)r).Entity);
								} else {
									result.Add(r);
								}
							}
						}
					}
				}				


			}
//.........这里部分代码省略.........

		IEnumerable<ICompletionData> CreateParameterCompletion(MethodGroupResolveResult resolveResult, CSharpResolver state, AstNode invocation, SyntaxTree unit, int parameter, bool controlSpace)
		{
			var result = new CompletionDataWrapper(this);
			var addedEnums = new HashSet<string>();
			var addedDelegates = new HashSet<string>();

			foreach (var method in resolveResult.Methods) {
				CreateParameterForInvocation(result, method, state, parameter, addedEnums, addedDelegates);
			}
			foreach (var methods in resolveResult.GetEligibleExtensionMethods (true)) {
				foreach (var method in methods) {
					if (resolveResult.Methods.Contains(method))
						continue;
					CreateParameterForInvocation(result, new ReducedExtensionMethod(method), state, parameter, addedEnums, addedDelegates);
				}
			}

			foreach (var method in resolveResult.Methods) {
				if (parameter < method.Parameters.Count && method.Parameters [parameter].Type.Kind == TypeKind.Delegate) {
					AutoSelect = false;
					AutoCompleteEmptyMatch = false;
				}
				foreach (var p in method.Parameters) {
					result.AddNamedParameterVariable(p);
				}
			}

			if (!controlSpace) {
				if (addedEnums.Count + addedDelegates.Count == 0) {
					return Enumerable.Empty<ICompletionData>();
				}
				AutoCompleteEmptyMatch = false;
				AutoSelect = false;
			}
			AddContextCompletion(result, state, invocation);

			//			resolver.AddAccessibleCodeCompletionData (ExpressionContext.MethodBody, cdc);
			//			if (addedDelegates.Count > 0) {
			//				foreach (var data in result.Result) {
			//					if (data is MemberCompletionData) 
			//						((MemberCompletionData)data).IsDelegateExpected = true;
			//				}
			//			}
			return result.Result;
		}

		IEnumerable<ICompletionData> CreateTypeAndNamespaceCompletionData(TextLocation location, ResolveResult resolveResult, AstNode resolvedNode, CSharpResolver state)
		{
			if (resolveResult == null || resolveResult.IsError) {
				return null;
			}
			var exprParent = resolvedNode.GetParent<Expression>();
			var unit = exprParent != null ? exprParent.GetParent<SyntaxTree>() : null;

			var astResolver = unit != null ? CompletionContextProvider.GetResolver(state, unit) : null;
			IType hintType = exprParent != null && astResolver != null ? 
			                 TypeGuessing.GetValidTypes(astResolver, exprParent).FirstOrDefault() :
			                 null;
			var result = new CompletionDataWrapper(this);
			var lookup = new MemberLookup(
				ctx.CurrentTypeDefinition,
				Compilation.MainAssembly
			);
			if (resolveResult is NamespaceResolveResult) {
				var nr = (NamespaceResolveResult)resolveResult;
				if (!(resolvedNode.Parent is UsingDeclaration || resolvedNode.Parent != null && resolvedNode.Parent.Parent is UsingDeclaration)) {
					foreach (var cl in nr.Namespace.Types) {
						if (hintType != null && hintType.Kind != TypeKind.Array && cl.Kind == TypeKind.Interface) {
							continue;
						}
						if (!lookup.IsAccessible(cl, false))
							continue;
						result.AddType(cl, false, IsAttributeContext(resolvedNode));
					}
				}
				foreach (var ns in nr.Namespace.ChildNamespaces) {
					result.AddNamespace(lookup, ns);
				}
			} else if (resolveResult is TypeResolveResult) {
				var type = resolveResult.Type;
				foreach (var nested in type.GetNestedTypes ()) {
					if (hintType != null && hintType.Kind != TypeKind.Array && nested.Kind == TypeKind.Interface) {
						continue;
					}
					var def = nested.GetDefinition();
					if (def != null && !lookup.IsAccessible(def, false))
						continue;
					result.AddType(nested, false);
				}
			}
			return result.Result;
		}

		void AddKeywords(CompletionDataWrapper wrapper, IEnumerable<string> keywords)
		{
			if (!IncludeKeywordsInCompletionList)
				return;
			foreach (string keyword in keywords) {
				if (wrapper.Result.Any(data => data.DisplayText == keyword))
					continue;
				wrapper.AddCustom(keyword);
			}
		}

		IEnumerable<ICompletionData> GetPartialCompletionData(ITypeDefinition type, string modifiers)
		{
			var wrapper = new CompletionDataWrapper(this);
			int declarationBegin = offset;
			int j = declarationBegin;
			for (int i = 0; i < 3; i++) {
				switch (GetPreviousToken(ref j, true)) {
					case "public":
					case "protected":
					case "private":
					case "internal":
					case "sealed":
					case "override":
					case "partial":
					case "async":
						declarationBegin = j;
						break;
					case "static":
						return null; // don't add override completion for static members
				}
			}

			var methods = new List<IUnresolvedMethod>();

			foreach (var part in type.Parts) {
				foreach (var method in part.Methods) {
					if (method.BodyRegion.IsEmpty) {
						if (GetImplementation(type, method) != null) {
							continue;
						}
						methods.Add(method);
					}
				}	
			}

			foreach (var method in methods) {
				wrapper.Add(factory.CreateNewPartialCompletionData(
					declarationBegin,
					method.DeclaringTypeDefinition,
					method
				)
				);
			} 

			return wrapper.Result;
		}

		IEnumerable<ICompletionData> HandleCatchClauseType(ExpressionResult identifierStart)
		{
			Func<IType, IType> typePred = delegate (IType type) {
				if (type.GetAllBaseTypes().Any(t => t.ReflectionName == "System.Exception"))
					return type;
				return null;
			};
			if (identifierStart.Node.Parent is CatchClause) {
				var wrapper = new CompletionDataWrapper(this);
				AddTypesAndNamespaces(
					wrapper,
					GetState(),
					identifierStart.Node,
					typePred,
					m => false
				);
				return wrapper.Result;
			}

			var resolveResult = ResolveExpression(identifierStart);
			return CreateCompletionData(
				location,
				resolveResult.Result,
				identifierStart.Node,
				resolveResult.Resolver,
				typePred
			);
		}

		IEnumerable<ICompletionData> HandleObjectInitializer(CompilationUnit unit, AstNode n)
		{
			var p = n.Parent;
			while (p != null && !(p is ObjectCreateExpression)) {
				p = p.Parent;
			}
			var parent = (ArrayInitializerExpression)n.Parent;
			if (parent.IsSingleElement)
				parent = (ArrayInitializerExpression)parent.Parent;
			if (p != null) {
				var contextList = new CompletionDataWrapper(this);
				var initializerResult = ResolveExpression(p, unit);
				if (initializerResult != null && initializerResult.Item1.Type.Kind != TypeKind.Unknown) {
					// check 3 cases:
					// 1) New initalizer { xpr
					// 2) Object initializer { prop = val1, field = val2, xpr
					// 3) Array initializer { new Foo (), a, xpr
					// in case 1 all object/array initializer options should be given - in the others not.

					AstNode prev = null;
					if (parent.Elements.Count > 1) {
						prev = parent.Elements.First();
						if (prev is ArrayInitializerExpression && ((ArrayInitializerExpression)prev).IsSingleElement) 
							prev = ((ArrayInitializerExpression)prev).Elements.FirstOrDefault();
					}

					if (prev != null && !(prev is NamedExpression)) {
						AddContextCompletion(contextList, GetState(), n, unit);
						// case 3)
						return contextList.Result;
					}

					foreach (var m in initializerResult.Item1.Type.GetMembers (m => m.IsPublic && (m.EntityType == EntityType.Property || m.EntityType == EntityType.Field))) {
						contextList.AddMember(m);
					}

					if (prev != null && (prev is NamedExpression)) {
						// case 2)
						return contextList.Result;
					}

					// case 1)

					// check if the object is a list, if not only provide object initalizers
					var list = typeof(System.Collections.IList).ToTypeReference().Resolve(Compilation);
					if (initializerResult.Item1.Type.Kind != TypeKind.Array && list != null) {
						var def = initializerResult.Item1.Type.GetDefinition(); 
						if (def != null && !def.IsDerivedFrom(list.GetDefinition()))
							return contextList.Result;
					}

					AddContextCompletion(contextList, GetState(), n, unit);
					return contextList.Result;
				}
			}
			return null;
		}

		void AddEnumMembers(CompletionDataWrapper completionList, IType resolvedType, CSharpResolver state)
		{
			if (resolvedType.Kind != TypeKind.Enum) {
				return;
			}
			string typeString = GetShortType(resolvedType, state);
			if (typeString.Contains(".")) {
				completionList.AddType(resolvedType, typeString);
			}
			foreach (var field in resolvedType.GetFields ()) {
				if (field.IsConst || field.IsStatic) {
					completionList.Result.Add(factory.CreateEntityCompletionData(
						field,
						typeString + "." + field.Name
					)
					);
				}
			}
			DefaultCompletionString = typeString;
		}

		IEnumerable<ICompletionData> CreateParameterCompletion(MethodGroupResolveResult resolveResult, CSharpResolver state, AstNode invocation, CompilationUnit unit, int parameter, bool controlSpace)
		{
			var result = new CompletionDataWrapper(this);
			var addedEnums = new HashSet<string>();
			var addedDelegates = new HashSet<string>();
			
			foreach (var method in resolveResult.Methods) {
				if (method.Parameters.Count <= parameter) {
					continue;
				}
				var resolvedType = method.Parameters [parameter].Type;
				if (resolvedType.Kind == TypeKind.Enum) {
					if (addedEnums.Contains(resolvedType.ReflectionName)) {
						continue;
					}
					addedEnums.Add(resolvedType.ReflectionName);
					AddEnumMembers(result, resolvedType, state);
				} else if (resolvedType.Kind == TypeKind.Delegate) {
					if (addedDelegates.Contains(resolvedType.ReflectionName))
						continue;
					string parameterDefinition = AddDelegateHandlers(result, resolvedType);
					string varName = "Handle" + method.Parameters [parameter].Type.Name + method.Parameters [parameter].Name;
					result.Result.Add(
						factory.CreateEventCreationCompletionData(
						varName,
						resolvedType,
						null,
						parameterDefinition,
						currentMember,
						currentType)
					);
				}
			}
			if (!controlSpace) {
				if (addedEnums.Count + addedDelegates.Count == 0) {
					return Enumerable.Empty<ICompletionData>();
				}
				AutoCompleteEmptyMatch = false;
				AutoSelect = false;
			}
			AddContextCompletion(result, state, invocation, unit);
			
			//			resolver.AddAccessibleCodeCompletionData (ExpressionContext.MethodBody, cdc);
			//			if (addedDelegates.Count > 0) {
			//				foreach (var data in result.Result) {
			//					if (data is MemberCompletionData) 
			//						((MemberCompletionData)data).IsDelegateExpected = true;
			//				}
			//			}
			return result.Result;
		}

		IEnumerable<ICompletionData> CreateTypeAndNamespaceCompletionData(TextLocation location, ResolveResult resolveResult, AstNode resolvedNode, CSharpResolver state)
		{
			if (resolveResult == null || resolveResult.IsError) {
				return null;
			}
			var exprParent = resolvedNode.GetParent<Expression>();
			var unit = exprParent != null ? exprParent.GetParent<CompilationUnit>() : null;

			var astResolver = unit != null ? new CSharpAstResolver(
				state,
				unit,
				CSharpParsedFile
			) : null;
			IType hintType = exprParent != null && astResolver != null ? 
				CreateFieldAction.GetValidTypes(astResolver, exprParent) .FirstOrDefault() :
				null;
			var result = new CompletionDataWrapper(this);
			if (resolveResult is NamespaceResolveResult) {
				var nr = (NamespaceResolveResult)resolveResult;
				if (!(resolvedNode.Parent is UsingDeclaration || resolvedNode.Parent != null && resolvedNode.Parent.Parent is UsingDeclaration)) {
					foreach (var cl in nr.Namespace.Types) {
						string name = cl.Name;
						if (hintType != null && hintType.Kind != TypeKind.Array && cl.Kind == TypeKind.Interface) {
							continue;
						}
						if (IsAttributeContext(resolvedNode) && name.EndsWith("Attribute") && name.Length > "Attribute".Length) {
							name = name.Substring(0, name.Length - "Attribute".Length);
						}
						result.AddType(cl, name);
					}
				}
				foreach (var ns in nr.Namespace.ChildNamespaces) {
					result.AddNamespace(ns.Name);
				}
			} else if (resolveResult is TypeResolveResult) {
				var type = resolveResult.Type;
				foreach (var nested in type.GetNestedTypes ()) {
					if (hintType != null && hintType.Kind != TypeKind.Array && nested.Kind == TypeKind.Interface) {
						continue;
					}
					result.AddType(nested, nested.Name);
				}
			}
			return result.Result;
		}

		string AddDelegateHandlers(CompletionDataWrapper completionList, IType delegateType, bool addSemicolon = true, bool addDefault = true)
		{
			IMethod delegateMethod = delegateType.GetDelegateInvokeMethod();
			var thisLineIndent = GetLineIndent(location.Line);
			string delegateEndString = EolMarker + thisLineIndent + "}" + (addSemicolon ? ";" : "");
			//bool containsDelegateData = completionList.Result.Any(d => d.DisplayText.StartsWith("delegate("));
			if (addDefault) {
				var oldDelegate = completionList.Result.FirstOrDefault(cd => cd.DisplayText == "delegate");
				if (oldDelegate != null)
					completionList.Result.Remove(oldDelegate);
				completionList.AddCustom(
					"delegate",
					"Creates anonymous delegate.",
					"delegate {" + EolMarker + thisLineIndent + IndentString + "|" + delegateEndString
				);
			}
			var sb = new StringBuilder("(");
			var sbWithoutTypes = new StringBuilder("(");
			for (int k = 0; k < delegateMethod.Parameters.Count; k++) {
				if (k > 0) {
					sb.Append(", ");
					sbWithoutTypes.Append(", ");
				}
				var parameterType = delegateMethod.Parameters [k].Type;
				sb.Append(GetShortType(parameterType, GetState()));
				sb.Append(" ");
				sb.Append(delegateMethod.Parameters [k].Name);
				sbWithoutTypes.Append(delegateMethod.Parameters [k].Name);
			}
			sb.Append(")");
			sbWithoutTypes.Append(")");
			completionList.AddCustom(
				"delegate" + sb,
				"Creates anonymous delegate.",
				"delegate" + sb + " {" + EolMarker + thisLineIndent + IndentString + "|" + delegateEndString
			);
			if (!completionList.Result.Any(data => data.DisplayText == sbWithoutTypes.ToString())) {
				completionList.AddCustom(
					sbWithoutTypes.ToString(),
					"Creates lambda expression.",
					sbWithoutTypes + " => |" + (addSemicolon ? ";" : "")
				);
			}
			/* TODO:Make factory method out of it.
			// It's  needed to temporarly disable inserting auto matching bracket because the anonymous delegates are selectable with '('
			// otherwise we would end up with () => )
			if (!containsDelegateData) {
				var savedValue = MonoDevelop.SourceEditor.DefaultSourceEditorOptions.Instance.AutoInsertMatchingBracket;
				MonoDevelop.SourceEditor.DefaultSourceEditorOptions.Instance.AutoInsertMatchingBracket = false;
				completionList.Result.CompletionListClosed += delegate {
					MonoDevelop.SourceEditor.DefaultSourceEditorOptions.Instance.AutoInsertMatchingBracket = savedValue;
				};
			}*/
			return sb.ToString();
		}

		void AddTypesAndNamespaces(CompletionDataWrapper wrapper, CSharpResolver state, AstNode node, Func<IType, IType> typePred = null, Predicate<IMember> memberPred = null, Action<ICompletionData, IType> callback = null)
		{
			var lookup = new MemberLookup(
				ctx.CurrentTypeDefinition,
				Compilation.MainAssembly
			);
			if (currentType != null) {
				for (var ct = currentType; ct != null; ct = ct.DeclaringTypeDefinition) {
					foreach (var nestedType in ct.NestedTypes) {
						string name = nestedType.Name;
						if (IsAttributeContext(node) && name.EndsWith("Attribute") && name.Length > "Attribute".Length) {
							name = name.Substring(0, name.Length - "Attribute".Length);
						}

						if (typePred == null) {
							wrapper.AddType(nestedType, name);
							continue;
						}

						var type = typePred(nestedType.Resolve(ctx));
						if (type != null) {
							var a2 = wrapper.AddType(type, name);
							if (a2 != null && callback != null) {
								callback(a2, type);
							}
						}
						continue;
					}
				}
				if (this.currentMember != null && !(node is AstType)) {
					var def = ctx.CurrentTypeDefinition ?? Compilation.MainAssembly.GetTypeDefinition(currentType);
					if (def != null) {
						bool isProtectedAllowed = true;
						foreach (var member in def.GetMembers ()) {
							if (member is IMethod && ((IMethod)member).FullName == "System.Object.Finalize") {
								continue;
							}
							if (member.EntityType == EntityType.Operator) {
								continue;
							}
							if (member.IsExplicitInterfaceImplementation) {
								continue;
							}
							if (!lookup.IsAccessible(member, isProtectedAllowed)) {
								continue;
							}

							if (memberPred == null || memberPred(member)) {
								wrapper.AddMember(member);
							}
						}
						var declaring = def.DeclaringTypeDefinition;
						while (declaring != null) {
							foreach (var member in declaring.GetMembers (m => m.IsStatic)) {
								if (memberPred == null || memberPred(member)) {
									wrapper.AddMember(member);
								}
							}
							declaring = declaring.DeclaringTypeDefinition;
						}
					}
				}
				foreach (var p in currentType.TypeParameters) {
					wrapper.AddTypeParameter(p);
				}
			}
			var scope = CSharpParsedFile.GetUsingScope(location).Resolve(Compilation);
			
			for (var n = scope; n != null; n = n.Parent) {
				foreach (var pair in n.UsingAliases) {
					wrapper.AddNamespace(pair.Key);
				}
				foreach (var u in n.Usings) {
					foreach (var type in u.Types) {
						if (!lookup.IsAccessible(type, false))
							continue;

						IType addType = typePred != null ? typePred(type) : type;
						if (addType != null) {
							string name = type.Name;
							if (IsAttributeContext(node) && name.EndsWith("Attribute") && name.Length > "Attribute".Length) {
								name = name.Substring(0, name.Length - "Attribute".Length);
							}
							var a = wrapper.AddType(addType, name);
							if (a != null && callback != null) {
								callback(a, type);
							}
						}
					}
				}
				
				foreach (var type in n.Namespace.Types) {
					if (!lookup.IsAccessible(type, false))
						continue;
					IType addType = typePred != null ? typePred(type) : type;
					if (addType != null) {
						var a2 = wrapper.AddType(addType, addType.Name);
						if (a2 != null && callback != null) {
							callback(a2, type);
						}
//.........这里部分代码省略.........

		IEnumerable<ICompletionData> CreateConstructorCompletionData(IType hintType)
		{
			var wrapper = new CompletionDataWrapper(this);
			var state = GetState();
			Func<IType, IType> pred = null;
			Action<ICompletionData, IType> typeCallback = null;
			var inferredTypesCategory = new Category("Inferred Types", null);
			var derivedTypesCategory = new Category("Derived Types", null);
			if (hintType != null) {
				if (hintType.Kind != TypeKind.Unknown) {
					var lookup = new MemberLookup(
						ctx.CurrentTypeDefinition,
						Compilation.MainAssembly
					);
					typeCallback = (data, t) => {
						//check if type is in inheritance tree.
						if (hintType.GetDefinition() != null &&
							t.GetDefinition() != null &&
							t.GetDefinition().IsDerivedFrom(hintType.GetDefinition())) {
							data.CompletionCategory = derivedTypesCategory;
						}
					};
					pred = t => {
						if (t.Kind == TypeKind.Interface && hintType.Kind != TypeKind.Array) {
							return null;
						}
						// check for valid constructors
						if (t.GetConstructors().Count() > 0) {
							bool isProtectedAllowed = currentType != null ? 
							                          currentType.Resolve(ctx).GetDefinition().IsDerivedFrom(t.GetDefinition()) : false;
							if (!t.GetConstructors().Any(m => lookup.IsAccessible(m, isProtectedAllowed))) {
								return null;
							}
						}

						// check derived types
						var typeDef = t.GetDefinition();
						var hintDef = hintType.GetDefinition();
						if (typeDef != null && hintDef != null && typeDef.IsDerivedFrom(hintDef)) {
							var newType = wrapper.AddType(t, true);
							if (newType != null) {
								newType.CompletionCategory = inferredTypesCategory;
							}
						}

						// check type inference
						var typeInference = new TypeInference(Compilation);
						typeInference.Algorithm = TypeInferenceAlgorithm.ImprovedReturnAllResults;

						var inferedType = typeInference.FindTypeInBounds(new [] { t }, new [] { hintType });
						if (inferedType != SpecialType.UnknownType) {
							var newType = wrapper.AddType(inferedType, true);
							if (newType != null) {
								newType.CompletionCategory = inferredTypesCategory;
							}
							return null;
						}
						return t;
					};
					if (!(hintType.Kind == TypeKind.Interface && hintType.Kind != TypeKind.Array)) {
						var hint = wrapper.AddType(hintType, true);
						if (hint != null) {
							DefaultCompletionString = hint.DisplayText;
							hint.CompletionCategory = derivedTypesCategory;
						}
					}
					if (hintType is ParameterizedType && hintType.TypeParameterCount == 1 && hintType.FullName == "System.Collections.Generic.IEnumerable") {
						var arg = ((ParameterizedType)hintType).TypeArguments.FirstOrDefault();
						if (arg.Kind != TypeKind.TypeParameter) {
							var array = new ArrayType(ctx.Compilation, arg, 1);
							wrapper.AddType(array, true);
						}
					}
				} else {
					var hint = wrapper.AddType(hintType, true);
					if (hint != null) {
						DefaultCompletionString = hint.DisplayText;
						hint.CompletionCategory = derivedTypesCategory;
					}
				}
			} 
			AddTypesAndNamespaces(wrapper, state, null, pred, m => false, typeCallback, true);
			if (hintType == null || hintType == SpecialType.UnknownType) {
				AddKeywords(wrapper, primitiveTypesKeywords.Where(k => k != "void"));
			}

			CloseOnSquareBrackets = true;
			AutoCompleteEmptyMatch = true;
			AutoCompleteEmptyMatchOnCurlyBracket = false;
			return wrapper.Result;
		}

		IEnumerable<ICompletionData> GetOverrideCompletionData(IUnresolvedTypeDefinition type, string modifiers)
		{
			var wrapper = new CompletionDataWrapper(this);
			var alreadyInserted = new List<IMember>();
			//bool addedVirtuals = false;

			int declarationBegin = offset;
			int j = declarationBegin;
			for (int i = 0; i < 3; i++) {
				switch (GetPreviousToken(ref j, true)) {
					case "public":
					case "protected":
					case "private":
					case "internal":
					case "sealed":
					case "override":
					case "partial":
					case "async":
						declarationBegin = j;
						break;
					case "static":
						return null; // don't add override completion for static members
				}
			}
			AddVirtuals(
				alreadyInserted,
				wrapper,
				modifiers,
				type.Resolve(ctx),
				declarationBegin
			);
			return wrapper.Result;
		}

		IEnumerable<ICompletionData> HandleEnumContext()
		{
			var syntaxTree = ParseStub("a", false);
			if (syntaxTree == null) {
				return null;
			}

			var curType = syntaxTree.GetNodeAt<TypeDeclaration>(location);
			if (curType == null || curType.ClassType != ClassType.Enum) {
				syntaxTree = ParseStub("a {}", false);
				var node = syntaxTree.GetNodeAt<AstType>(location);
				if (node != null) {
					var wrapper = new CompletionDataWrapper(this);
					AddKeywords(wrapper, validEnumBaseTypes);
					return wrapper.Result;
				}
			}

			var member = syntaxTree.GetNodeAt<EnumMemberDeclaration>(location);
			if (member != null && member.NameToken.EndLocation < location) {
				if (currentMember == null && currentType != null) {
					foreach (var a in currentType.Members)
						if (a.Region.Begin < location && (currentMember == null || a.Region.Begin > currentMember.Region.Begin))
							currentMember = a;
				}
				bool isComplete = false;
				return DefaultControlSpaceItems(ref isComplete);
			}

			var attribute = syntaxTree.GetNodeAt<Attribute>(location);
			if (attribute != null) {
				var contextList = new CompletionDataWrapper(this);
				var astResolver = CompletionContextProvider.GetResolver(GetState(), syntaxTree);
				var csResolver = astResolver.GetResolverStateBefore(attribute);
				AddContextCompletion(
					contextList,
					csResolver,
					attribute
				);
				return contextList.Result;
			}
			return null;
		}

		protected virtual void AddVirtuals(List<IMember> alreadyInserted, CompletionDataWrapper col, string modifiers, IType curType, int declarationBegin)
		{
			if (curType == null) {
				return;
			}
			foreach (var m in curType.GetMembers ().Reverse ()) {
				if (curType.Kind != TypeKind.Interface && !m.IsOverridable) {
					continue;
				}
				// filter out the "Finalize" methods, because finalizers should be done with destructors.
				if (m is IMethod && m.Name == "Finalize") {
					continue;
				}

				var data = factory.CreateNewOverrideCompletionData(
					declarationBegin,
					currentType,
					m
				);
				// check if the member is already implemented
				bool foundMember = curType.GetMembers().Any(cm => SignatureComparer.Ordinal.Equals(
					cm,
					m
				) && cm.DeclaringTypeDefinition == curType.GetDefinition()
				);
				if (foundMember) {
					continue;
				}
				if (alreadyInserted.Any(cm => SignatureComparer.Ordinal.Equals(cm, m)))
					continue;
				alreadyInserted.Add(m);
				data.CompletionCategory = col.GetCompletionCategory(m.DeclaringTypeDefinition);
				col.Add(data);
			}
		}

		IEnumerable<ICompletionData> HandleAccessorContext()
		{
			var unit = ParseStub("get; }", false);
			var node = unit.GetNodeAt(location, cn => !(cn is CSharpTokenNode));
			if (node is Accessor) {
				node = node.Parent;
			}
			var contextList = new CompletionDataWrapper(this);
			if (node is PropertyDeclaration || node is IndexerDeclaration) {
				if (IncludeKeywordsInCompletionList) {
					contextList.AddCustom("get");
					contextList.AddCustom("set");
					AddKeywords(contextList, accessorModifierKeywords);
				}
			} else if (node is CustomEventDeclaration) {
				if (IncludeKeywordsInCompletionList) {
					contextList.AddCustom("add");
					contextList.AddCustom("remove");
				}
			} else {
				return null;
			}

			return contextList.Result;
		}