Поделиться через

  • Статья

XDocument.Load Method (XmlReader, LoadOptions)

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

Creates a new XDocument from an XmlReader, optionally setting the base URI, and retaining line information.

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

Syntax

'Declaration
Public Shared Function Load ( _
    reader As XmlReader, _
    options As LoadOptions _
) As XDocument

public static XDocument Load(
    XmlReader reader,
    LoadOptions options
)

Parameters

Return Value

Type: System.Xml.Linq.XDocument
An XDocument that contains the XML that was read from the specified XmlReader.

Remarks

Use Parse to create an XDocument from a string that contains XML.

Setting PreserveWhitespace is not valid when loading from a XmlReader. The XmlReader will be configured to either read whitespace or not. The LINQ to XML tree will be populated with the whitespace nodes that the reader surfaces. This will be the behavior regardless of whether PreserveWhitespace is set or not.

The XmlReader may have a valid base URI or not. If you set SetBaseUri, the base URI will be set in the XML tree from the base URI that is reported by the XmlReader.

The XmlReader may have a valid line information or not. If you set SetLineInfo, the line information will be set in the XML tree from the line information that is reported by the XmlReader.

There is a performance penalty if you set the SetLineInfo flag.

The line information is accurate immediately after loading the XML document. If you modify the XML tree after loading the document, the line information may become meaningless.

Examples

The following example loads the line information that it loads from the XmlReader. It then prints the line information.

Dim output As New StringBuilder
Dim markup As String = _
    "<Root>" & Environment.NewLine & _
    "    <Child>" & Environment.NewLine & _
    "        <GrandChild/>" & Environment.NewLine & _
    "    </Child>" & Environment.NewLine & _
    "</Root>"

' Create a reader and move to the content.
Using nodeReader As XmlReader = XmlReader.Create(New StringReader(markup))

    ' The reader must be in the Interactive state in order to
    ' create a LINQ to XML tree from it.
    nodeReader.MoveToContent()

    Dim xRoot As XDocument = XDocument.Load(nodeReader, LoadOptions.SetLineInfo)
    output.Append(String.Format("{0}{1}{2}", _
        "Element Name".PadRight(20), _
        "Line".PadRight(5), _
        "Position"))
    output.Append(Environment.NewLine)
    output.Append(String.Format("{0}{1}{2}", _
        "------------".PadRight(20), _
        "----".PadRight(5), _
        "--------"))
    output.Append(Environment.NewLine)
    For Each e As XElement In xRoot.Elements("Root").DescendantsAndSelf()
        output.Append(String.Format("{0}{1}{2}", _
            ("".PadRight(e.Ancestors().Count() * 2) & e.Name.ToString()).PadRight(20), _
            (DirectCast(e, IXmlLineInfo)).LineNumber.ToString().PadRight(5), _
            (DirectCast(e, IXmlLineInfo)).LinePosition))
        output.Append(Environment.NewLine)
    Next
End Using

OutputTextBlock.Text = output.ToString()

StringBuilder output = new StringBuilder();
string markup =
@"<Root>
        <Child>
            <GrandChild/>
        </Child>
    </Root>";

// Create a reader and move to the content.
using (XmlReader nodeReader = XmlReader.Create(new StringReader(markup)))
{
    // the reader must be in the Interactive state in order to
    // Create a LINQ to XML tree from it.
    nodeReader.MoveToContent();

    XDocument xRoot = XDocument.Load(nodeReader, LoadOptions.SetLineInfo);
    output.Append("Element Name".PadRight(20) +
                    "Line".PadRight(5) +
                    "Position" + Environment.NewLine);
    output.Append("------------".PadRight(20) +
                    "----".PadRight(5) +
                    "--------" + Environment.NewLine);
    foreach (XElement e in xRoot.Elements("Root").DescendantsAndSelf())
        output.Append(("".PadRight(e.Ancestors().Count() * 2) + e.Name).PadRight(20) +
                    ((IXmlLineInfo)e).LineNumber.ToString().PadRight(5) +
                    ((IXmlLineInfo)e).LinePosition + Environment.NewLine);
}

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.