Reads the content as an object of the type specified.
Namespace:
System.Xml
Assembly:
System.Xml (in System.Xml.dll)
Visual Basic (Declaration)
Public Overridable Function ReadContentAs ( _
returnType As Type, _
namespaceResolver As IXmlNamespaceResolver _
) As Object
Dim instance As XmlReader
Dim returnType As Type
Dim namespaceResolver As IXmlNamespaceResolver
Dim returnValue As Object
returnValue = instance.ReadContentAs(returnType, _
namespaceResolver)
public virtual Object ReadContentAs(
Type returnType,
IXmlNamespaceResolver namespaceResolver
)
public:
virtual Object^ ReadContentAs(
Type^ returnType,
IXmlNamespaceResolver^ namespaceResolver
)
public function ReadContentAs(
returnType : Type,
namespaceResolver : IXmlNamespaceResolver
) : Object
Parameters
- returnType
- Type: System..::.Type
The type of the value to be returned.
Note: |
|---|
With the release of the .NET Framework 3.5, the value of the returnType parameter can now be the DateTimeOffset type. |
- namespaceResolver
- Type: System.Xml..::.IXmlNamespaceResolver
An IXmlNamespaceResolver object that is used to resolve any namespace prefixes related to type conversion. For example, this can be used when converting an XmlQualifiedName object to an xs:string.
This value can be nullNothingnullptra null reference (Nothing in Visual Basic).
Return Value
Type:
System..::.ObjectThe concatenated text content or attribute value converted to the requested type.
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.
The following example uses the ReadContentAs method to return the contents of the colors element into an array of string objects.
Using reader As XmlReader = XmlReader.Create("dataFile_2.xml")
reader.ReadToDescendant("item")
reader.MoveToAttribute("colors")
Dim colors As String() = CType(reader.ReadContentAs(GetType(String()), Nothing), String())
Dim color As String
For Each color In colors
Console.WriteLine("Colors: {0}", color)
Next color
End Using
using (XmlReader reader = XmlReader.Create("dataFile_2.xml")) {
reader.ReadToDescendant("item");
reader.MoveToAttribute("colors");
string[] colors = (string[]) reader.ReadContentAs(typeof(string[]),null);
foreach (string color in colors) {
Console.WriteLine("Colors: {0}", color);
}
}
The example uses the dataFile_2.xml file as input.
<root>
<item sale-item='true' productID='123456' colors='blue green black'>
<price>9.95</price>
</item>
<item sale-item='false' productID='124390'>
<price>5.95</price>
</item>
<item sale-item='true' productID='53298'>
<price>12.95</price>
</item>
</root>
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0
.NET Compact Framework
Supported in: 3.5, 2.0
XNA Framework
Supported in: 3.0, 2.0, 1.0
Reference
Other Resources