XPathNavigator.ValueAsBoolean Property

Definition

Namespace:

System.Xml.XPath

Assembly:

System.Xml.ReaderWriter.dll

Source:

XPathNavigator.cs

Gets the current node's value as a Boolean.

public:
 virtual property bool ValueAsBoolean { bool get(); };

public override bool ValueAsBoolean { get; }

member this.ValueAsBoolean : bool

Public Overrides ReadOnly Property ValueAsBoolean As Boolean

Property Value

Boolean

The current node's value as a Boolean.

Exceptions

FormatException

The current node's string value cannot be converted to a Boolean.

InvalidCastException

The attempted cast to Boolean is not valid.

Examples

In the following example, the value of each element in the valueas.xml file is returned using the ValueAsBoolean, ValueAsDateTime, ValueAsDouble, ValueAsInt, and ValueAsLong properties.

XPathDocument^ document = gcnew XPathDocument("valueas.xml");
XPathNavigator^ navigator = document->CreateNavigator();

// ValueAsBoolean
navigator->MoveToChild("root", "");
navigator->MoveToChild("booleanElement", "");
bool^ booleanValue = navigator->ValueAsBoolean;
Console::WriteLine(navigator->LocalName + ": " + booleanValue);

// ValueAsDateTime
navigator->MoveToNext("dateTimeElement", "");
DateTime^ dateTimeValue = navigator->ValueAsDateTime;
Console::WriteLine(navigator->LocalName + ": " + dateTimeValue);

// ValueAsDouble, ValueAsInt32, ValueAsInt64, ValueAsSingle
navigator->MoveToNext("numberElement", "");
Double doubleValue = navigator->ValueAsDouble;
Int32 int32Value = navigator->ValueAsInt;
Int64 int64Value = navigator->ValueAsLong;
Console::WriteLine(navigator->LocalName + ": " + doubleValue);
Console::WriteLine(navigator->LocalName + ": " + int32Value);
Console::WriteLine(navigator->LocalName + ": " + int64Value);

XPathDocument document = new XPathDocument("valueas.xml");
XPathNavigator navigator = document.CreateNavigator();

// ValueAsBoolean
navigator.MoveToChild("root", "");
navigator.MoveToChild("booleanElement", "");
bool booleanValue = navigator.ValueAsBoolean;
Console.WriteLine(navigator.LocalName + ": " + booleanValue);

// ValueAsDateTime
navigator.MoveToNext("dateTimeElement", "");
DateTime dateTimeValue = navigator.ValueAsDateTime;
Console.WriteLine(navigator.LocalName + ": " + dateTimeValue);

// ValueAsDouble, ValueAsInt32, ValueAsInt64, ValueAsSingle
navigator.MoveToNext("numberElement", "");
Double doubleValue = navigator.ValueAsDouble;
Int32 int32Value = navigator.ValueAsInt;
Int64 int64Value = navigator.ValueAsLong;
Console.WriteLine(navigator.LocalName + ": " + doubleValue);
Console.WriteLine(navigator.LocalName + ": " + int32Value);
Console.WriteLine(navigator.LocalName + ": " + int64Value);

Dim document As XPathDocument = New XPathDocument("valueas.xml")
Dim navigator As XPathNavigator = document.CreateNavigator()

' ValueAsBoolean
navigator.MoveToChild("root", "")
navigator.MoveToChild("booleanElement", "")
Dim booleanValue As Boolean = navigator.ValueAsBoolean
Console.WriteLine(navigator.LocalName + ": " + booleanValue)

' ValueAsDateTime
navigator.MoveToNext("dateTimeElement", "")
Dim dateTimeValue As DateTime = navigator.ValueAsDateTime
Console.WriteLine(navigator.LocalName + ": " + dateTimeValue)

' ValueAsDouble, ValueAsInt32, ValueAsInt64, ValueAsSingle
navigator.MoveToNext("numberElement", "")
Dim doubleValue As Double = navigator.ValueAsDouble
Dim int32Value As Int32 = navigator.ValueAsInt
Dim int64Value As Int64 = navigator.ValueAsLong
Console.WriteLine(navigator.LocalName + ": " + doubleValue)
Console.WriteLine(navigator.LocalName + ": " + int32Value)
Console.WriteLine(navigator.LocalName + ": " + int64Value)

The example takes the valueas.xml file as an input.

<root>  
    <booleanElement>true</booleanElement>  
    <dateTimeElement>2004-04-20T12:00:00</dateTimeElement>  
    <decimalElement>10.00</decimalElement>  
    <numberElement>100000000</numberElement>  
</root>  

Remarks

If the XPathNavigator has schema or type information (for example, from an XmlDocument object initialized with an XML schema validating XmlReader), and if the current node is defined as an XML Schema xs:boolean type, the ValueAsBoolean property returns the current node's value as an unboxed Boolean object.

However, if the XPathNavigator does not have any schema or type information, the ValueAsBoolean property attempts to convert the string value of the current node to a Boolean value, according to the XPath 2.0 casting rules for xs:boolean.