如何由XSD自动生成XML和实体类(引用) 项目中有时候要用XML作为数据源，因此需要定义XML文件和相应的类，最佳方法是首先定义XSD，然后自动生成实体类，最后生成XML和填充数据；读取XML数据源的时候，首先用XSD验证XML数据格式，然后自动读入实体类使用。
定义XSD的过程就是类似设计表结构的过程，二者也可以相互转化。
本文讨论了如何定义XSD文件（XML Schema），然后自动生成实体类，最后生成XML的过程，以及如何根据XSD验证XML文件的合法性。以供大家做项目时参考。
1. 首先在VS2005中添加一个XSD文件。
2. 使用VS2005工具XSD.exe(SDK"v2.0"Bin"xsd.exe)自动生成实体类：
xsd /c /namespace:myCompany /language:CS temp1.xsd
也可以生成DataSet类型的类:
xsd /dataset /language:CS temp1.xsd
( 类文件和XSD之间可以相互转换，也就是说，你也可以先生成类，然后自动生成XSD)
自动读取XML数据到实体类：
XmlSerializer xs = new XmlSerializer(typeof(myClassType));using (FileStream fs = new FileStream(XmlFilePath, FileMode.Open)){return (myClassType)xs.Deserialize(fs);}3. 如何由XSD生成XML？
- 可以用其他工具，如XMLSpy，DTD/Schema -> Generate sample XML file...- 可以由XSD生成类，然后写代码实例化这个类，最后序列化为XML
- 如何自动给类每个属性设置一个空值：(用反射的方法)
代码示例：
/** <summary>/// Get all properties and set default value/// </summary>/// <typeparam name="T">Type</typeparam>/// <param name="item">Object</param>private static void ReflctProperties<T>(T item){PropertyInfo[] pty = typeof(T).GetProperties();Type t = item.GetType();
if (pty != null){foreach (PropertyInfo info in pty){if (!info.CanWrite) continue;
if (info.PropertyType == typeof(String)){t.GetProperty(info.Name).SetValue(item, String.Empty, null);}if (info.PropertyType == typeof(Boolean)){t.GetProperty(info.Name).SetValue(item, true, null);}}}}
- 反射读取类的属性:
public static object GetProperty<T>(T item, string PropertyName){PropertyInfo propertyInfo = item.GetType().GetProperty(PropertyName);if (propertyInfo != null){ return propertyInfo.GetValue(item, null);}return null;}
- 如何序列化为XML？
/**//**//** <summary>/// Serialize class instance to XML file/// </summary>/// <typeparam name="T">type</typeparam>/// <param name="XMLFileToCreate">XMLFileToCreate</param>/// <param name="instance">class instance</param>public void Serialize<T>(string XMLFileToCreate, T instance){if (instance == null) return;
XmlSerializer xs = new XmlSerializer(typeof(T));using (StreamWriter sw = new StreamWriter(XMLFileToCreate)){xs.Serialize(sw, instance);}}
4. 如何使用XSD来验证XML文件合法性： - 使用XMLSpy，首先Assign XSD,然后验证 （其实就是设置XML里面引用的schema，注意schema可能引用其他的schema）- 代码中验证：Validate XML against XSDValidate XML against XSD#region Validate XML against XSD
public class Validator{private string errMsg;
/**//**//** <summary>/// validation Error Msg/// </summary>public string validationErrMsg{get { return errMsg; }set { errMsg = value; }} /**//**//** <summary>/// Validate XML against schema/// </summary>/// <param name="XSD"></param>/// <param name="XMLFile"></param>/// <param name="LocationDefined"></param>/// <returns></returns>public bool Validate(string XSD, string XMLFile, bool LocationDefined){bool isValid = true;
try{Stream schemaFile = null;
XmlReaderSettings settings = new XmlReaderSettings();ValidationEventHandler SchemaValidationEventHandler = new ValidationEventHandler(ValidationCallBack);
settings.ValidationType = ValidationType.Schema;settings.ValidationFlags |= XmlSchemaValidationFlags.AllowXmlAttributes;settings.ValidationFlags |= XmlSchemaValidationFlags.ReportValidationWarnings;settings.ValidationEventHandler += SchemaValidationEventHandler;
if (LocationDefined == true){settings.ValidationFlags |= XmlSchemaValidationFlags.ProcessInlineSchema;settings.ValidationFlags |= XmlSchemaValidationFlags.ProcessSchemaLocation;}else{schemaFile = new FileStream(XSD, FileMode.Open); XmlSchema tmsSchema = XmlSchema.Read(schemaFile, SchemaValidationEventHandler);
settings.Schemas.Add(tmsSchema);}
using (XmlReader reader = XmlReader.Create(XMLFile, settings)){string test;
while (reader.Read() && isValid == true){test = reader.Name;}};
if (schemaFile != null){schemaFile.Close();}}catch (Exception e){validationErrMsg += "Exception occured when validating. " + e.Message;
isValid = false;}
return isValid;}
/**//**//** <summary>/// Display any warnings or errors./// </summary>/// <param name="sender"></param>/// <param name="args"></param>public void ValidationCallBack(object sender, ValidationEventArgs args){if (args.Severity == XmlSeverityType.Warning){validationErrMsg += "Matching schema not found. No validation occurred." + args.Message;validationErrMsg = args.Message;}else{validationErrMsg += "/nValidation error: " + args.Message;
validationErrMsg = args.Message;}}}#endregion
