The WriteStartElement method creates the start tag of an element. After that, we call the WriteElementString method four times with different values that writes an element containing the string value. Then we call the WriteEndElement method that writes the end tag of the start tag.
The last call the code is made to the Flush method that flushes whatever is in the buffer. Listing 2 generates output that looks like Figure 1. Let's take a quick look at the XmlWriterSettings class properties. I know it looks and reads like a lot of documentation but if you want to write good XML, you must understand the XmlWritersSettings properties.
The CheckCharacters property gets or sets a value indicating whether to do character checking. The CloseOutput property gets or sets a value indicating whether the XmlWriter should also close the underlying stream when the Close method is called. The ConformanceLevel property gets or sets the level of conformance that the XmlWriter complies with. You may overwrite the default encoding of an XML document. The Encoding property gets or sets the type of text encoding to use.
The Indent property gets or sets a value indicating whether to indent elements. The IndentChars property gets or sets the character string to use when indenting. This setting is used when the Indent property is set to true. The NamespaceHanding property gets or sets a value that indicates whether the XmlWriter should remove duplicate namespace declarations when writing XML content.
The default behavior is for the writer to output all namespace declarations that are present in the writer's namespace resolver. The NewLineChars property gets or sets the character string to use for line breaks. The NewLineHandling property gets or sets a value indicating whether to normalize line breaks in the output. The NewLineOnAttributes property gets or sets a value indicating whether to write attributes on a new line. The OutputMethod property gets the method used to serialize the XmlWriter output.
The WriteEndDocumentOnClose property gets or sets a value that indicates whether the XmlWriter will add closing tags to all unclosed element tags when the Close method is called. Alright, now you are familiar with the XmlWriterSettings properties, let's create an XML document to apply these settings. Create method. The code snippet in Listing 3 creates an XmlWriter with some features by setting the XmlWriter settings.
WriteElementString "title" , book. Title ; writer. WriteElementString "author" , book. Name ; writer. WriteElementString "publisher" , book. Publisher ; writer. WriteElementString "price" , book. ToString ; writer. Fragment; writerSettings. NET" ; writer. WriteElementString "publisher" , "APress" ; writer. Create Console. This class is an abstract base class for many useful classes for inserting, removing, and replacing nodes, navigating through the document.
It also contains properties to get a parent or child, name, last child, node type and more. XmlDocument class represents an XML document and provides methods and properties to load and save a document. It also provides functionality to add XML items such as attributes, comments, spaces, elements, and new nodes. XmlDocumentFragment class represents a document fragment, which can be used to add to a document. NET data set objects. In spite of above discussed classes, System.
Xml namespace contains more classes. Next namespace in Xml series is System. Serialization namespace contains classes that are used to serialize objects into XML format documents or streams. This class contains many Move methods to move through a document. This file comes with VS. NET samples. You can search this on your machine and change the path of the file in the following line:.
Besides XmlReader methods and properties, these classes also contain members to read text, node, and schemas respectively. You read a file by passing file name as a parameter in constructor. After read method is called, you can read all information and data stored in a document. The NodeType property of XmlTextReader is important when you want to know the content type of a document. List 2 code sample reads an XML document, finds a node type and writes information at the end with how many node types a document has.
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After reading a node, I check its NodeType property to find the node and write node contents to the console and keep track of number of particular type of nodes. In the end, I display total number of different types of nodes in the document. XmlWriter class contains the functionality to write to XML documents. It contains methods and properties to write to XML documents.
This class has several Writexxx method to write every type of item of an XML document. Some of these methods are used in a start and end pair. Besides many methods, this class has three properties. The WriteState gets and sets the state of the XmlWriter class.
First thing we need to do is create an instance of XmlTextWriter using its constructor. XmlTextWriter has three overloaded constructors, which can take a string, stream, or a TextWriter as an argument.
You must have to open a document before start writing to it. WriteComment method writes comment to a document. Because one of the constructors takes a variable number of arguments, you can pass any number of child elements. Of course, each of those child elements can contain their own child elements. For any element, you can add any number of attributes. If the new content already is parented, and is part of another XML tree, the new content is cloned, and the newly cloned content is attached to the XML tree.
The last example in this article demonstrates this. To create a contacts XElement , you could use the following code:. If indented properly, the code to construct XElement objects closely resembles the structure of the underlying XML.
The XElement class uses the following constructors for functional construction. Note that there are some other constructors for XElement , but because they're not used for functional construction they're not listed here. The content parameter is extremely flexible. It supports any type of object that's a valid child of an XElement. The following rules apply to different types of objects passed in this parameter:.
You can create an XElement that contains simple content with a single method call. To do this, specify the content as the second parameter, as follows:.
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