C# CodeWriter.GetVariableExpression方法代码示例

        /// <summary>
        /// Writes property setter, for FK properties
        /// </summary>
        /// <param name="writer"></param>
        /// <param name="property"></param>
        /// <param name="relatedAssociations"></param>
        /// <param name="context"></param>
        private void WriteClassPropertyAccessorSet(CodeWriter writer, Column property, IEnumerable<Association> relatedAssociations, GenerationContext context)
        {
            // if new value if different from old one
            using (writer.WriteIf(writer.GetDifferentExpression(writer.GetPropertySetValueExpression(),
                                                                writer.GetVariableExpression(property.Storage))))
            {
                // if the property is used as a FK, we ensure that it hasn't been already loaded or assigned
                foreach (var relatedAssociation in relatedAssociations)
                {
                    // first thing to check: ensure the association backend isn't already affected.
                    // if it is the case, then the property must not be manually set

                    // R# considers the following as an error, but the csc doesn't
                    //var memberName = ReflectionUtility.GetMemberInfo<DbLinq.Data.Linq.EntityRef<object>>(e => e.HasLoadedOrAssignedValue).Name;
                    var memberName = "HasLoadedOrAssignedValue";
                    using (writer.WriteIf(writer.GetMemberExpression(relatedAssociation.Storage, memberName)))
                    {
                        writer.WriteLine(writer.GetThrowStatement(writer.GetNewExpression(
                                                                      writer.GetMethodCallExpression(
                                                                          writer.GetLiteralFullType(
                                                                              typeof(
                                                                                  System.Data.Linq.
                                                                                  ForeignKeyReferenceAlreadyHasValueException
                                                                                  )))
                                                                      )));
                    }
                }
                // the before and after are used by extensions related to interfaces
                // for example INotifyPropertyChanged
                // here the code before the change
                foreach (IImplementation implementation in context.Implementations())
                    implementation.WritePropertyBeforeSet(writer, property, context);
                // property assignment
                writer.WriteLine(
                    writer.GetStatement(
                        writer.GetAssignmentExpression(writer.GetVariableExpression(property.Storage),
                                                       writer.GetPropertySetValueExpression())));
                // here the code after change
                foreach (IImplementation implementation in context.Implementations())
                    implementation.WritePropertyAfterSet(writer, property, context);
            }
        }

        protected virtual void WriteClassEqualsAndHash(CodeWriter writer, Table table, GenerationContext context)
        {
            List<DbLinq.Schema.Dbml.Column> primaryKeys = table.Type.Columns.Where(c => c.IsPrimaryKey).ToList();
            if (primaryKeys.Count == 0)
            {
                writer.WriteLine("#warning L189 table {0} has no primary key. Multiple C# objects will refer to the same row.",
                                 table.Name);
                return;
            }

            using (writer.WriteRegion(string.Format("GetHashCode(), Equals() - uses column {0} to look up objects in liveObjectMap",
                                                    string.Join(", ", primaryKeys.Select(pk => pk.Member).ToList().ToArray()))))
            {
                // GetHashCode
                using (writer.WriteMethod(SpecificationDefinition.Public | SpecificationDefinition.Override,
                                          "GetHashCode", typeof(int)))
                {
                    string hashCode = null;

                    foreach (var primaryKey in primaryKeys)
                    {
                        var member = writer.GetVariableExpression(primaryKey.Storage);
                        string primaryKeyHashCode = writer.GetMethodCallExpression(writer.GetMemberExpression(member, "GetHashCode"));
                        if (primaryKey.CanBeNull
                        || GetType(primaryKey.Type, false).IsClass) // this patch to ensure that even if DB does not allow nulls,
                        // our in-memory object won't generate a fault
                        {
                            var isNullExpression = writer.GetEqualExpression(member, writer.GetNullExpression());
                            var nullExpression = writer.GetLiteralValue(0);
                            primaryKeyHashCode = "(" + writer.GetTernaryExpression(isNullExpression, nullExpression, primaryKeyHashCode) + ")";
                        }
                        if (string.IsNullOrEmpty(hashCode))
                            hashCode = primaryKeyHashCode;
                        else
                            hashCode = writer.GetXOrExpression(hashCode, primaryKeyHashCode);
                    }
                    writer.WriteLine(writer.GetReturnStatement(hashCode));
                }
                writer.WriteLine();

                // Equals
                string otherAsObject = "o";
                using (writer.WriteMethod(SpecificationDefinition.Public | SpecificationDefinition.Override,
                                          "Equals", typeof(bool), new ParameterDefinition { Type = typeof(object), Name = otherAsObject }))
                {
                    string other = "other";
                    writer.WriteLine(writer.GetStatement(writer.GetAssignmentExpression(
                                                             writer.GetDeclarationExpression(other, table.Type.Name),
                                                             writer.GetCastExpression(otherAsObject, table.Type.Name,
                                                                                      false))));
                    using (writer.WriteIf(writer.GetEqualExpression(other, writer.GetNullExpression())))
                    {
                        writer.WriteLine(writer.GetReturnStatement(writer.GetLiteralValue(false)));
                    }
                    string andExpression = null;
                    foreach (var primaryKey in primaryKeys)
                    {
                        var member = writer.GetVariableExpression(primaryKey.Storage);
                        string primaryKeyTest = writer.GetMethodCallExpression(
                                writer.GetMemberExpression(
                                    writer.GetMemberExpression(
                                        writer.GetGenericName("System.Collections.Generic.EqualityComparer", primaryKey.Type),
                                        "Default"),
                                    "Equals"),
                                member,
                                writer.GetMemberExpression(other, member));
                        if (string.IsNullOrEmpty(andExpression))
                            andExpression = primaryKeyTest;
                        else
                            andExpression = writer.GetAndExpression(andExpression, primaryKeyTest);
                    }
                    writer.WriteLine(writer.GetReturnStatement(andExpression));
                }
            }
        }

        /// <summary>
        /// Writes property accessor
        /// </summary>
        /// <param name="writer"></param>
        /// <param name="property"></param>
        /// <param name="relatedAssociations"></param>
        /// <param name="context"></param>
        protected virtual void WriteClassPropertyAccessors(CodeWriter writer, Column property, IEnumerable<Association> relatedAssociations, GenerationContext context)
        {
            //generate [Column(...)] attribute
            var column = NewAttributeDefinition<ColumnAttribute>();
            column["Storage"] = property.Storage;
            column["Name"] = property.Name;
            column["DbType"] = property.DbType;
            // be smart: we only write attributes when they differ from the default values
            var columnAttribute = new ColumnAttribute();
            if (property.IsPrimaryKey != columnAttribute.IsPrimaryKey)
                column["IsPrimaryKey"] = property.IsPrimaryKey;
            if (property.IsDbGenerated != columnAttribute.IsDbGenerated)
                column["IsDbGenerated"] = property.IsDbGenerated;
            if (property.AutoSync != DbLinq.Schema.Dbml.AutoSync.Default)
                column["AutoSync"] = new EnumFullname("AutoSync", property.AutoSync);
            if (property.CanBeNull != columnAttribute.CanBeNull)
                column["CanBeNull"] = property.CanBeNull;
            if (property.Expression != null)
                column["Expression"] = property.Expression;

            var specifications = property.AccessModifierSpecified
                                     ? GetSpecificationDefinition(property.AccessModifier)
                                     : SpecificationDefinition.Public;
            if (property.ModifierSpecified)
                specifications |= GetSpecificationDefinition(property.Modifier);

            //using (WriteAttributes(writer, context.Parameters.MemberExposedAttributes))
            using (WriteAttributes(writer, GetAttributeNames(context, context.Parameters.MemberAttributes)))
            using (writer.WriteAttribute(NewAttributeDefinition<DebuggerNonUserCodeAttribute>()))
            using (writer.WriteAttribute(column))
            using (writer.WriteProperty(specifications, property.Member, GetTypeOrExtendedType(writer, property)))
            {
                // on auto storage, we're just lazy
                if (property.Storage == null)
                    writer.WriteAutomaticPropertyGetSet();
                else
                {
                    using (writer.WritePropertyGet())
                    {
                        writer.WriteLine(writer.GetReturnStatement(writer.GetVariableExpression(property.Storage)));
                    }
                    using (writer.WritePropertySet())
                    {
                        WriteClassPropertyAccessorSet(writer, property, relatedAssociations, context);
                    }
                }
            }
        }