Any validation errors will invoke the Validation Event Handler method.Inside this method, a String Builder object keeps appending the contents of the validation error message to itself. NET Framework gave you some capable tools for validating XML data. NET Framework 2.0 augments the original capabilities significantly. NET 1.x's XML validation features, providing new classes and methods that are not only standards-compliant, but also easy to use. An XML file is usually validated for its conformance to a particular schema or a DTD.I'll show you how to take advantage of some of these features, which will translate to better-performing, more standards-compliant XML data in your applications. The XML schema file is usually an XML-Data Reduced (XDR) or XML Schema Definition (XSD) file.Validating an XML document with an XSD schema requires five steps. Second, create an instance of the Xml Reader Settings object.The Xml Reader Settings class lets you specify a set of options the Xml Reader object will support, and these options will govern the effects when parsing XML data. Note that the Xml Reader Settings class renders the Xml Validating Reader class used with . Third, associate the Xml Reader Settings class with the already defined Validation Event Handler method.The Xml Schema Set class replaces the Xml Schema Collection class, the preferred class for caching schemas in . The new Xml Schema Set class provides much better standards compliance and better performance.
You specify the validation settings as well as a Validation Event Handler method using the Xml Reader Settings object. I won't explain how to validate XML data using DTDs because those are not typically used outside legacy applications.So far, you've seen how to perform validation using the standalone XSD schema file through the Xml Reader Settings class.This approach is an excellent way to validate XML data, but it doesn't provide a neat and efficient way of reusing XML schemas.Next, add the file to the Schemas collection of the Xml Reader Settings object and invoke the static Create method of the Xml Reader object, passing in the path of the file and the Xml Reader Settings object.