This method reads the text content at the current reader position and converts it to the requested return type. Text, white space, significant white space and CDATA sections are concatenated. Comments and processing instructions are skipped and entity references are automatically resolved.
This method is used to read, convert if necessary, and return atomic value items from the current node content. If the input type is a valid mappings for the type of the current node then an instance of the target type containing the value of the current node is returned. The Mapping XML Data Types to CLR Types topic has a list of the default mappings.
For example, if you had the following XML text:
<elem>123 <!-- comment --> <?pi my_text?> 456 <?pi another_pi?></elem>
If the data is typed and a string array is supplied to the ReadContentAs method call, then the integer values are converted from strings according to the list of valid CLR type mappings.
If the data is untyped and a string array is supplied to the ReadContentAs method call, then the content is parsed into separate strings. An array containing two strings is returned with the values "123" and "456". The spaces are not preserved from the content.
In general when reading untyped data the content is parsed according to the supplied type. For example, if an integer array is supplied to the ReadContentAs method call then the string is parsed into an array of integers {123,456}.
In the following example the XML text is not separated by spaces
<elem>123<!-- comment --><?pi my_text?>456789<?pi another_pi?></elem>
If the content is untyped and a string array is supplied to the ReadContentAs method call then an array containing one concatenated string is returned with the value "123456789".
The following table describes how this method treats each node type.
XmlNodeType | Return value | Reader behavior |
|---|
Text
CDATA
Whitespace
SignificantWhitespace
EntityReference
EndEntity
| Concatenated content of text, CDATA, white space and significant white space nodes converted to the requested type. | Moves to the next start element or end element tag. Entity references are automatically expanded. |
Attribute
| Same as calling XmlConvert.ToXxx on the attribute value. | The reader remains in the current position. |
Comment
ProcessingInstruction
| Ignores the processing instruction (PI) or comment and reads the concatenated text content that follows the PI or comment. | Moves to the next start element or end element tag. Entity references are automatically expanded. |
EndElement
| An empty string. | The reader remains in the current position. |
Element
XmlDeclaration
None
Document
DocumentType
Notation
Entity
DocumentFragment
| An InvalidOperationException is thrown. | Undefined, although typically the reader remains in the current position. |
For more information, see Reading Typed Data and the W3C XML Schema Part 2: Datatypes recommendation.