Articolo
11/18/2011

XmlReader.ReadContentAsBoolean Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Reads the text content at the current position as a Boolean.

Namespace: System.Xml
Assembly: System.Xml (in System.Xml.dll)

Syntax

'Declaration
Public Overridable Function ReadContentAsBoolean As Boolean

public virtual bool ReadContentAsBoolean()

Return Value

Type: System.Boolean
The text content as a Boolean object.

Exceptions

Exception	Condition
InvalidCastException	The attempted cast is not valid.
FormatException	The string format is not valid.

Remarks

This method concatenates text, white space, significant white space, and CDATA sections, and skips any comments or processing instructions. Entity references are automatically resolved.

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.

Examples

Dim output As New StringBuilder()

Dim xmlString As String = _
    "<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>"


Using reader As XmlReader = XmlReader.Create(New StringReader(xmlString))

    reader.ReadToDescendant("item")
    Do
        reader.MoveToAttribute("sale-item")
        Dim onSale As Boolean = reader.ReadContentAsBoolean()
        If onSale Then
            output.AppendLine(reader("productID"))
        End If
    Loop While reader.ReadToNextSibling("item")

    OutputTextBlock.Text = output.ToString()
End Using

StringBuilder output = new StringBuilder();

String xmlString =
    @"<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>";

using (XmlReader reader = XmlReader.Create(new StringReader(xmlString)))
{
    reader.ReadToDescendant("item");
    do
    {
        reader.MoveToAttribute("sale-item");
        Boolean onSale = reader.ReadContentAsBoolean();
        if (onSale)
        {
            output.AppendLine(reader["productID"]);
        }
    } while (reader.ReadToNextSibling("item"));

}

OutputTextBlock.Text = output.ToString();

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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