Applied XML Programming for Microsoft .NET.pdf - Csbdu.in

Table 3-6: Mapping Between XSD and .NET TypesXSD Type .NET Type DescriptionintegerQName System.Xml.XmlQualifiedName An XML qualifiednameshort System.Int16 16-bit signed integerstring System.String A string typetime System.DateTime An instant in timetimePeriod System.DateTime A period of timetoken System.String Normalized string withleading and trailingwhite spaces removedunsignedByte System.Byte 8-bit unsigned integerunsignedInt System.UInt32 32-bit unsigned integerunsignedLong System.UInt64 64-bit unsigned integerunsignedShort System.UInt16 16-bit unsigned integerThe schema compiler is a piece of code that translates between XSD types and thetype system of a particular platform. In the .NET Framework, the schema compilercompiles XSD into an XmlSchema object that exposes the schema information throughmethods and properties.Effective serialization between XSD and binary classes on a given platform is a featurewith tremendous potential. It could supersede today's XML parsing by automaticallycreating an instance of a class instead of creating a generic and unwieldy XML DOM orsimply passing raw data to the application. In the .NET Framework, XML serialization isaccomplished using the XmlSerializer class and exploiting the services of the XMLSchema definition tool (xsd.exe). I'll cover XML serialization extensively in Chapter 11.NoteThe XML Schema definition tool (xsd.exe) is an executableavailable with the .NET Framework SDK. You'll find it in the BINsubdirectory of the .NET Framework installation path. Normally, thispath is C:\Program Files\Microsoft Visual Studio.NET\FrameworkSDK.Among other things, xsd.exe can generate a C# or Visual Basicclass from an XSD file and infer an XSD from a source XML file.This tool is also responsible for all the XSD-related magic performedby Visual Studio .NET.Defining an XSD SchemaYou have three options when creating an XSD schema. You can write it manually bycombining the various tags defined by the XML Schema specification. A more effectiveoption is represented by Visual Studio .NET, which provides a visual editor for XSD fileswith full IntelliSense support. The third option is based on the XML Schema definitiontool (xsd.exe) mentioned in the previous section, which can infer the underlying schemafrom any well-formed XML document.Of these options, the first is certainly the hardest to code and the one that you willprobably use less frequently. It also happens to be the most useful tool for gaining an90