.NET : 如何动态根据一个业务实体类型创建XSD架构文件

这是正在开发的XML数据库的一个功能，我需要动态根据一个业务实体类型创建一个XSD架构文件，并使用其对最后的XML数据文件进行约束。

目前该功能仅仅是一个原型，还有待细化改进。例如在实体的成员上用一些特定的Attribute标明该成员要被保存的形态。

第一部分：业务实体类

(作为演示目的，我将所有的类型定义在一个文件里，同时每个类都只有少量简单的属性成员）

此处特别注意的是，Order这个类是很复杂的，它包含了一系列的OrderItem，而OrderItem又包含了Product对象。

using System;
using System.Collections.Generic;
using System.Text; 

namespace DataEntities
{
    public class Order
    {
        public int OrderID { get; set; }
        public string CustomerID { get; set; }
        public int EmployeeID { get; set; }
        public DateTime OrderDate { get; set; }
        public List<OrderItem> OrderItems { get; set; } 

        public override string ToString()
        {
            StringBuilder sb = new StringBuilder();
            sb.AppendFormat("\t{0}\t{1}\t{2}\t{3}", OrderID, CustomerID, EmployeeID, OrderDate);
            sb.AppendLine();
            foreach (var item in OrderItems)
            {
                sb.AppendFormat("\t\t{0}\t{1}\t{2}\n", item.Product.ProductName, item.UnitPrice, item.Quantity);
            }
            return sb.ToString();
        } 

    } 
    public class OrderItem 
    {
        public int OrderId { get; set; }
        public Product Product { get; set; }
        public decimal UnitPrice { get; set; }
        public decimal Quantity { get; set; }

    }
    public class Product 
    {
        public int ProductId { get; set; }
        public string ProductName { get; set; }

    }
}

第二部分：生成XSD的工具类(Utility.cs)

using System;
using System.Xml.Linq;
using System.Collections;
using System.Xml;

namespace XMLDatabase
{
    public class Utility
    {
        /// <summary>
        /// 使用指定类型生成一个架构文件
        /// </summary>
        /// <typeparam name="T"></typeparam>
        public static void XsdGenerate<T>(XmlWriter xw) {
            Type t = typeof(T);

            XNamespace xn = "http://www.w3.org/2001/XMLSchema";
            XDocument doc = new XDocument(
                new XDeclaration("1.0", "utf-8", "yes"),
                new XElement(xn + "schema",
                    new XAttribute("elementFormDefault", "qualified"),
                    new XAttribute(XNamespace.Xmlns + "xs", "http://www.w3.org/2001/XMLSchema"),
                    new XElement(xn+"element",
                        new XAttribute("name","Table"),
                        new XAttribute("nillable","true"),
                        new XAttribute("type","Table"))
                    ));


            XElement tableElement = new XElement(xn + "complexType",
                new XAttribute("name", "Table"));

            tableElement.Add(
                new XElement(xn + "sequence",
                    new XElement(xn + "element",
                        new XAttribute("minOccurs", "0"),
                        new XAttribute("maxOccurs", "unbounded"),
                        new XAttribute("name","Row"),
                        new XAttribute("type",t.Name)
                        )),
                new XElement(xn + "attribute",
                    new XAttribute("name", "CreateTime"),
                    new XAttribute("type", "xs:string"))
                        );

            doc.Root.Add(tableElement);

            CreateComplexType(t, doc.Root);
            doc.Save(xw);

        }


        private static void CreateComplexType(Type t,XElement root) {

            XNamespace xn = root.GetNamespaceOfPrefix("xs");
            XElement temp = new XElement(
                xn + "complexType",
                new XAttribute("name", t.Name));
            #region 循环所有属性

            foreach (var p in t.GetProperties())//循环所有属性
            {
                Type pType = p.PropertyType;
                string fullType = pType.FullName;

                //这里仍然是分几种情况
                if (!GeneralType.Contains(fullType))
                {

                    var seqelement = temp.Element(xn + "sequence");
                    if (seqelement == null)
                    {
                        seqelement = new XElement(xn + "sequence");
                        temp.AddFirst(seqelement);
                    }

                    if (pType.IsEnum)//如果是枚举
                    {
                        seqelement.Add(
                            new XElement(
                                xn + "element",
                                new XAttribute("minOccurs", "0"),
                                new XAttribute("maxOccurs", "1"),
                                new XAttribute("name", p.Name),
                                new XAttribute("type", pType.Name)));

                        XElement enumElement = new XElement(
                            xn + "complexType",
                            new XAttribute("name", pType.Name),
                            new XElement(xn + "attribute",
                                new XAttribute("name", "Enum"),
                                new XAttribute("type", "xs:string")));
                        root.Add(enumElement);

                    }
                    else if (pType.GetInterface(typeof(IList).FullName) != null && pType.IsGenericType)
                        //如果是集合,并且是泛型集合
                    {

                        Type itemType = pType.GetGenericArguments()[0];
                        seqelement.Add(
                            new XElement(
                                xn + "element",
                                new XAttribute("minOccurs", "0"),
                                new XAttribute("maxOccurs", "1"),
                                new XAttribute("name", p.Name),
                                new XAttribute("type", "ArrayOf"+p.Name)));

                        XElement arrayElement = new XElement(
                            xn + "complexType",
                            new XAttribute("name", "ArrayOf" + p.Name),
                            new XElement(xn + "sequence",
                                new XElement(xn + "element",
                                    new XAttribute("minOccurs", "0"),
                                    new XAttribute("maxOccurs", "unbounded"),
                                    new XAttribute("name", itemType.Name),
                                    new XAttribute("type", itemType.Name))));

                        root.Add(arrayElement);

                        CreateComplexType(itemType, root);

                    }
                    else if (pType.IsClass || pType.IsValueType)
                    {
                        seqelement.Add(
                            new XElement(
                                xn + "element",
                                new XAttribute("minOccurs", "0"),
                                new XAttribute("maxOccurs", "1"),
                                new XAttribute("name", p.Name),
                                new XAttribute("type", pType.Name)));

                        CreateComplexType(pType, root);
                    }
                }
                else
                {
                    //这种情况最简单，属性为标准内置类型，直接作为元素的Attribute即可
                    temp.Add(
                        new XElement(xn + "attribute",
                            new XAttribute("name", p.Name),
                            new XAttribute("type", GeneralType.ConvertXSDType(pType.FullName))));

                }

            }
            #endregion

            temp.Add(new XElement(xn + "attribute",
                new XAttribute("name", "TypeName"),
                new XAttribute("type", "xs:string")));

            root.Add(temp);
        }

    }
}

第三部分：辅助类型(GeneralType.cs).

这个类型中有一个方法可以将业务实体类型成员属性的类型转换为XSD中 的类型。

using System;
using System.Collections.Generic;
using System.Text;

namespace XMLDatabase
{
    public class GeneralType
    {
        private static readonly List<string> generalTypes = new List<string>()
        {
            "System.Byte",//typeof(byte).FullName,
            "System.SByte",//typeof(sbyte).FullName,
            "System.Int16",//typeof(short).FullName,
            "System.UInt16",//typeof(ushort).FullName,
            "System.Int32",//typeof(int).FullName,
            "System.UInt32",//typeof(uint).FullName,
            "System.Int64",//typeof(long).FullName,
            "System.UInt64",//typeof(ulong).FullName,
            "System.Double",//typeof(double).FullName,
            "System.Decimal",//typeof(decimal).FullName,
            "System.Single",//typeof(float).FullName,
            "System.Char",//typeof(char).FullName,
            "System.Boolean",//typeof(bool).FullName,
            "System.String",//typeof(string).FullName,
            "System.DateTime"//typeof(DateTime).FullName
        };


        /// <summary>
        /// 判断当前给定类型是否为默认的数据类型
        /// </summary>
        /// <param name="fullType"></param>
        /// <returns></returns>
        public static bool Contains(string fullType)
        {
            return generalTypes.Contains(fullType);
        }


        public static string ConvertXSDType(string fullType)
        {
            switch (fullType)
            {
                case "System.String":
                    return "xs:string";
                case "System.Int32":
                    return "xs:int";
                case "System.DateTime":
                    return "xs:dateTime";
                case "System.Boolean":
                    return "xs:boolean";
                case "System.Single":
                    return "xs:float";
                case "System.Byte":
                    return "xs:byte";
                case "System.SByte":
                    return "xs:unsignedByte";
                case "System.Int16":
                    return "xs:short";
                case "System.UInt16":
                    return "xs:unsignedShort";
                case "System.UInt32":
                    return "xs:unsignedInt";
                case "System.Int64":
                    return "xs:long";
                case "System.UInt64":
                    return "xs:unsignedLong";
                case "System.Double":
                    return "xs:double";
                case "System.Decimal":
                    return "xs:decimal";

                default:
                    break;
            }

            return string.Empty;
        }
        
    }
}

第四部分：单元测试

        /// <summary>
        ///XsdGenerate 的测试
        ///</summary>
        public void XsdGenerateTestHelper<T>()
        {
            XmlWriter xw = XmlWriter.Create("Order.xsd"); // TODO: 初始化为适当的值
            Utility.XsdGenerate<Order>(xw);

            xw.Close();
        }

第五部分： 生成的结果

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<xs:schema elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="Table" nillable="true" type="Table" />
  <xs:complexType name="Table">
    <xs:sequence>
      <xs:element minOccurs="0" maxOccurs="unbounded" name="Row" type="Order" />
    </xs:sequence>
    <xs:attribute name="CreateTime" type="xs:string" />
  </xs:complexType>
  <xs:complexType name="ArrayOfOrderItems">
    <xs:sequence>
      <xs:element minOccurs="0" maxOccurs="unbounded" name="OrderItem" type="OrderItem" />
    </xs:sequence>
  </xs:complexType>
  <xs:complexType name="Product">
    <xs:attribute name="ProductId" type="xs:int" />
    <xs:attribute name="ProductName" type="xs:string" />
    <xs:attribute name="TypeName" type="xs:string" />
  </xs:complexType>
  <xs:complexType name="OrderItem">
    <xs:sequence>
      <xs:element minOccurs="0" maxOccurs="1" name="Product" type="Product" />
    </xs:sequence>
    <xs:attribute name="OrderId" type="xs:int" />
    <xs:attribute name="UnitPrice" type="xs:decimal" />
    <xs:attribute name="Quantity" type="xs:decimal" />
    <xs:attribute name="TypeName" type="xs:string" />
  </xs:complexType>
  <xs:complexType name="Order">
    <xs:sequence>
      <xs:element minOccurs="0" maxOccurs="1" name="OrderItems" type="ArrayOfOrderItems" />
    </xs:sequence>
    <xs:attribute name="OrderID" type="xs:int" />
    <xs:attribute name="CustomerID" type="xs:string" />
    <xs:attribute name="EmployeeID" type="xs:int" />
    <xs:attribute name="OrderDate" type="xs:dateTime" />
    <xs:attribute name="TypeName" type="xs:string" />
  </xs:complexType>
</xs:schema>

第六部分：合法的数据文件范例

<?xml version="1.0" encoding="utf-8"?>
<Table Name="Orders" CreateTime="2009/8/9 21:59:04">
  <Row TypeName="DataEntities.Order" OrderID="10249" CustomerID="ABCDEF" EmployeeID="1" OrderDate="2009-08-09T21:59:04.125+08:00">
    <OrderItems>
      <OrderItem TypeName="DataEntities.OrderItem" OrderId="10249" UnitPrice="25" Quantity="4">
        <Product TypeName="DataEntities.Product" ProductId="1" ProductName="Pen" />
      </OrderItem>
      <OrderItem TypeName="DataEntities.OrderItem" OrderId="10249" UnitPrice="2" Quantity="2000">
        <Product TypeName="DataEntities.Product" ProductId="1" ProductName="Car" />
      </OrderItem>
    </OrderItems>
  </Row>
  <Row TypeName="DataEntities.Order" OrderID="10249" CustomerID="ABCDEF" EmployeeID="1" OrderDate="2009-08-10T07:29:51.546875+08:00">
    <OrderItems>
      <OrderItem TypeName="DataEntities.OrderItem" OrderId="10249" UnitPrice="25" Quantity="4">
        <Product TypeName="DataEntities.Product" ProductId="1" ProductName="Pen" />
      </OrderItem>
      <OrderItem TypeName="DataEntities.OrderItem" OrderId="10249" UnitPrice="2" Quantity="2000">
        <Product TypeName="DataEntities.Product" ProductId="1" ProductName="Car" />
      </OrderItem>
    </OrderItems>
  </Row>
  <Row TypeName="DataEntities.Order" OrderID="10249" CustomerID="ABCDEF" EmployeeID="1" OrderDate="2009-08-10T07:30:13.375+08:00">
    <OrderItems>
      <OrderItem TypeName="DataEntities.OrderItem" OrderId="10249" UnitPrice="25" Quantity="4">
        <Product TypeName="DataEntities.Product" ProductId="1" ProductName="Pen" />
      </OrderItem>
      <OrderItem TypeName="DataEntities.OrderItem" OrderId="10249" UnitPrice="2" Quantity="2000">
        <Product TypeName="DataEntities.Product" ProductId="1" ProductName="Car" />
      </OrderItem>
    </OrderItems>
  </Row>
  <Row TypeName="DataEntities.Order" OrderID="10249" CustomerID="ABCDEF" EmployeeID="1" OrderDate="2009-08-10T07:30:43.875+08:00">
    <OrderItems>
      <OrderItem TypeName="DataEntities.OrderItem" OrderId="10249" UnitPrice="25" Quantity="4">
        <Product TypeName="DataEntities.Product" ProductId="1" ProductName="Pen" />
      </OrderItem>
      <OrderItem TypeName="DataEntities.OrderItem" OrderId="10249" UnitPrice="2" Quantity="2000">
        <Product TypeName="DataEntities.Product" ProductId="1" ProductName="Car" />
      </OrderItem>
    </OrderItems>
  </Row>
</Table>

本文由作者：陈希章 于 2009/8/10 11:55:00 发布在：博客园,转载请注明出处