C# TypeUsage类代码示例

 /// <summary>
 ///     Given a clrType attempt to return the corresponding target type from
 ///     the worksapce
 /// </summary>
 /// <param name="clrType"> The clr type to resolve </param>
 /// <param name="outTypeUsage"> an out param for the typeUsage to be resolved to </param>
 /// <returns> true if a TypeUsage can be found for the target type </returns>
 internal bool TryGetType(Type clrType, out TypeUsage outTypeUsage)
 {
     return TryGetTypeByName(
         clrType.FullNameWithNesting(),
         false /*ignoreCase*/,
         out outTypeUsage);
 }

        /// <summary>
        ///     Look up a type in the target data space based upon the fullName
        /// </summary>
        /// <param name="fullName"> fullName </param>
        /// <param name="ignoreCase"> true for case-insensitive lookup </param>
        /// <param name="typeUsage"> The type usage object to return </param>
        /// <returns> True if the retrieval succeeded </returns>
        internal override bool TryGetTypeByName(string fullName, bool ignoreCase, out TypeUsage typeUsage)
        {
            typeUsage = null;
            Map map = null;

            // From ClrPerspective, we should not allow anything from SSpace. So make sure that the CSpace type does not
            // have the Target attribute
            if (MetadataWorkspace.TryGetMap(fullName, DataSpace.OSpace, ignoreCase, DataSpace.OCSpace, out map))
            {
                // Check if it's primitive type, if so, then use the MetadataWorkspace to get the mapped primitive type
                if (map.EdmItem.BuiltInTypeKind
                    == BuiltInTypeKind.PrimitiveType)
                {
                    // Reassign the variable with the provider primitive type, then create the type usage
                    var primitiveType = MetadataWorkspace.GetMappedPrimitiveType(
                        ((PrimitiveType)map.EdmItem).PrimitiveTypeKind, DataSpace.CSpace);
                    if (primitiveType != null)
                    {
                        typeUsage = EdmProviderManifest.Instance.GetCanonicalModelTypeUsage(primitiveType.PrimitiveTypeKind);
                    }
                }
                else
                {
                    Debug.Assert(((GlobalItem)map.EdmItem).DataSpace == DataSpace.CSpace);
                    typeUsage = GetMappedTypeUsage(map);
                }
            }

            return (null != typeUsage);
        }

        internal DbUnaryExpression(DbExpressionKind kind, TypeUsage resultType, DbExpression argument)
            : base(kind, resultType)
        {
            Debug.Assert(argument != null, "DbUnaryExpression.Argument cannot be null");

            _argument = argument;
        }

        public override TypeUsage GetEdmType(TypeUsage storeType)
        {
            if (storeType == null)
              {
            throw new ArgumentNullException("storeType");
              }

              string storeTypeName = storeType.EdmType.Name.ToLowerInvariant();

              if (!base.StoreTypeNameToEdmPrimitiveType.ContainsKey(storeTypeName))
              {
            throw new ArgumentException(String.Format("The underlying provider does not support the type '{0}'.", storeTypeName));
              }

              PrimitiveType edmPrimitiveType = base.StoreTypeNameToEdmPrimitiveType[storeTypeName];

              if (edmPrimitiveType.PrimitiveTypeKind == PrimitiveTypeKind.Binary)
              {
            return TypeUsage.CreateBinaryTypeUsage(edmPrimitiveType, false);
              }

              if (edmPrimitiveType.PrimitiveTypeKind == PrimitiveTypeKind.String)
              {
            Facet facet;
            if (storeType.Facets.TryGetValue("MaxLength", false, out facet) && !facet.IsUnbounded && facet.Value != null)
              return TypeUsage.CreateStringTypeUsage(edmPrimitiveType, false, false, (int)facet.Value);
            else
              return TypeUsage.CreateStringTypeUsage(edmPrimitiveType, false, false);
              }

              return TypeUsage.CreateDefaultTypeUsage(edmPrimitiveType);
        }

        internal DbUnaryExpression(DbExpressionKind kind, TypeUsage resultType, DbExpression argument)
            : base(kind, resultType)
        {
            DebugCheck.NotNull(argument);

            _argument = argument;
        }

        private static EdmFunction ResolveCanonicalFunction(string functionName, TypeUsage[] argumentTypes)
        {
            DebugCheck.NotEmpty(functionName);

            var functions = new List<EdmFunction>(
                EdmProviderManifest.Instance.GetStoreFunctions().Where(
                    func => string.Equals(func.Name, functionName, StringComparison.Ordinal))
                );

            EdmFunction foundFunction = null;
            var ambiguous = false;
            if (functions.Count > 0)
            {
                foundFunction = FunctionOverloadResolver.ResolveFunctionOverloads(functions, argumentTypes, false, out ambiguous);
                if (ambiguous)
                {
                    throw new ArgumentException(Strings.Cqt_Function_CanonicalFunction_AmbiguousMatch(functionName));
                }
            }

            if (foundFunction == null)
            {
                throw new ArgumentException(Strings.Cqt_Function_CanonicalFunction_NotFound(functionName));
            }

            return foundFunction;
        }

 /// <summary>
 ///     Initializes a new instance of the  class.
 /// </summary>
 /// <param name = "type">The data type for this column.</param>
 /// <param name = "typeUsage">
 ///     Additional details about the data type.
 ///     This includes details such as maximum length, nullability etc.
 /// </param>
 public ColumnModel(PrimitiveTypeKind type, TypeUsage typeUsage)
 {
     _type = type;
     _typeUsage = typeUsage;
     _clrType = PrimitiveType.GetEdmPrimitiveType(_type).ClrEquivalentType;
     _clrDefaultValue = CreateDefaultValue();
 }

 /// <summary>
 /// Initializes a new instance of EdmMember class
 /// </summary>
 /// <param name="name">name of the member</param>
 /// <param name="memberTypeUsage">type information containing info about member's type and its facet</param>
 internal EdmMember(string name, TypeUsage memberTypeUsage)
 {
     EntityUtil.CheckStringArgument(name, "name");
     EntityUtil.GenericCheckArgumentNull(memberTypeUsage, "memberTypeUsage");
     _name = name;
     _typeUsage = memberTypeUsage;
 }

 public override TypeUsage GetEdmType(TypeUsage storeType)
 {
     string storeTypeName = storeType.EdmType.Name.ToLower();
     PrimitiveType edmPrimitiveType = base.StoreTypeNameToEdmPrimitiveType[storeTypeName];
     if (storeTypeName == "string" || storeTypeName == "varchar")
     {
         Facet f;
         int maxLength = -1;
         if (storeType.Facets.TryGetValue("MaxLength", false, out f) && !f.IsUnbounded && f.Value != null)
             maxLength = (int)f.Value;
         if (maxLength != -1)
             return TypeUsage.CreateStringTypeUsage(edmPrimitiveType, false, false, maxLength);
         else
             return TypeUsage.CreateStringTypeUsage(edmPrimitiveType, false, false);
     }
     else if (storeTypeName == "decimal" || storeTypeName == "numeric")
     {
         Facet f;
         byte precision = 0;
         if (storeType.Facets.TryGetValue("Precision", false, out f) && !f.IsUnbounded && f.Value != null)
             precision = (byte)f.Value;
         byte scale = 0;
         if (storeType.Facets.TryGetValue("Scale", false, out f) && !f.IsUnbounded && f.Value != null)
             scale = (byte)f.Value;
         if (precision != 0 && scale != 0)
             return TypeUsage.CreateDecimalTypeUsage(edmPrimitiveType, precision, scale);
         else
             return TypeUsage.CreateDecimalTypeUsage(edmPrimitiveType);
     }
     else
         return TypeUsage.CreateDefaultTypeUsage(edmPrimitiveType);
     throw new NotImplementedException();
 }

 /// <summary>
 /// Initializes a new instance of the navigation property class
 /// </summary>
 /// <param name="name">name of the navigation property</param>
 /// <param name="typeUsage">TypeUsage object containing the navigation property type and its facets</param>
 /// <exception cref="System.ArgumentNullException">Thrown if name or typeUsage arguments are null</exception>
 /// <exception cref="System.ArgumentException">Thrown if name argument is empty string</exception>
 internal NavigationProperty(string name, TypeUsage typeUsage)
     : base(name, typeUsage)
 {
     EntityUtil.CheckStringArgument(name, "name");
     EntityUtil.GenericCheckArgumentNull(typeUsage, "typeUsage");
     _accessor = new NavigationPropertyAccessor(name);
 }

        private static EdmFunction ResolveCanonicalFunction(string functionName, TypeUsage[] argumentTypes)
        {
            Debug.Assert(!string.IsNullOrEmpty(functionName), "Function name must not be null");

            List<EdmFunction> functions = new List<EdmFunction>(
                System.Linq.Enumerable.Where(
                    EdmProviderManifest.Instance.GetStoreFunctions(),
                    func => string.Equals(func.Name, functionName, StringComparison.Ordinal))
            );

            EdmFunction foundFunction = null;
            bool ambiguous = false;
            if (functions.Count > 0)
            {
                foundFunction = EntitySql.FunctionOverloadResolver.ResolveFunctionOverloads(functions, argumentTypes, false, out ambiguous);
                if (ambiguous)
                {
                    throw EntityUtil.Argument(Strings.Cqt_Function_CanonicalFunction_AmbiguousMatch(functionName));
                }
            }

            if (foundFunction == null)
            {
                throw EntityUtil.Argument(Strings.Cqt_Function_CanonicalFunction_NotFound(functionName));
            }

            return foundFunction;
        }

 /// <summary>
 /// The constructor for constructing a CollectionType object with the element type (as a TypeUsage) it contains
 /// </summary>
 /// <param name="elementType">The element type that this collection type contains</param>
 /// <exception cref="System.ArgumentNullException">Thrown if the argument elementType is null</exception>
 internal CollectionType(TypeUsage elementType)
     : base(GetIdentity(EntityUtil.GenericCheckArgumentNull(elementType, "elementType")), 
             EdmConstants.TransientNamespace, elementType.EdmType.DataSpace)
 {
     _typeUsage = elementType;
     SetReadOnly();
 }

        internal static void MapPrimitivePropertyFacets(
            EdmProperty property, EdmProperty column, TypeUsage typeUsage)
        {
            DebugCheck.NotNull(property);
            DebugCheck.NotNull(column);
            DebugCheck.NotNull(typeUsage);

            if (IsValidFacet(typeUsage, XmlConstants.FixedLengthElement))
            {
                column.IsFixedLength = property.IsFixedLength;
            }

            if (IsValidFacet(typeUsage, XmlConstants.MaxLengthElement))
            {
                column.IsMaxLength = property.IsMaxLength;
                column.MaxLength = property.MaxLength;
            }

            if (IsValidFacet(typeUsage, XmlConstants.UnicodeElement))
            {
                column.IsUnicode = property.IsUnicode;
            }

            if (IsValidFacet(typeUsage, XmlConstants.PrecisionElement))
            {
                column.Precision = property.Precision;
            }

            if (IsValidFacet(typeUsage, XmlConstants.ScaleElement))
            {
                column.Scale = property.Scale;
            }
        }

 // <summary>
 // Use this constructor if the symbol represents a SqlStatement for which the output columns need to be tracked.
 // </summary>
 public Symbol(string name, TypeUsage type, Dictionary<string, Symbol> outputColumns, bool outputColumnsRenamed)
 {
     this.name = name;
     NewName = name;
     Type = type;
     this.outputColumns = outputColumns;
     OutputColumnsRenamed = outputColumnsRenamed;
 }

        internal DbFunctionAggregate(TypeUsage resultType, DbExpressionList arguments, EdmFunction function, bool isDistinct)
            : base(resultType, arguments)
        {
            DebugCheck.NotNull(function);

            _aggregateFunction = function;
            _distinct = isDistinct;
        }