Статья
11/18/2011

XmlWriter.WriteString Method

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

When overridden in a derived class, writes the given text content.

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

Syntax

'Declaration
Public MustOverride Sub WriteString ( _
    text As String _
)

public abstract void WriteString(
    string text
)

Parameters

text
Type: System.String
The text to write.

Exceptions

Exception	Condition
ArgumentException	The text string contains an invalid surrogate pair.

Remarks

WriteString does the following:

The characters &, <, and > are replaced with &, <, and >, respectively.
The default behavior of an XmlWriter created using Create is to throw an ArgumentException when attempting to write character values in the range 0x-0x1F (excluding white space characters 0x9, 0xA, and 0xD). These invalid XML characters can be written by creating the XmlWriter with the CheckCharacters property set to false. Doing so will result in the characters being replaced with numeric character entities ( through &#0x1F). Note Microsoft does not encourage the practice of writing invalid XML characters since many applications that consume XML are not designed to handle invalid characters.
If WriteString is called in the context of an attribute value, double and single quotes are replaced with " and ' respectively.

For example, this input string test<item>test is written out as

 test&lt;item&gt;test

If text is either nulla null reference (Nothing in Visual Basic) or String.Empty, this method writes a text node with no data content.

Examples

The following example navigates through the stream to determine the current node type, and then uses XmlWriter to output the XmlReader content.

Dim output As StringBuilder = New StringBuilder()

Dim xmlString As String = "<?xml version='1.0'?>" & _
                "<!-- This is a sample XML document -->" & _
                "<Items>" & _
                  "<Item>test with a child element <more/> stuff</Item>" & _
                "</Items>"
' Create an XmlReader
Using reader As XmlReader = XmlReader.Create(New StringReader(xmlString))
    Dim ws As XmlWriterSettings = New XmlWriterSettings()
    ws.Indent = True
    Using writer As XmlWriter = XmlWriter.Create(output, ws)

        ' Parse the file and display each of the nodes.
        While reader.Read()
            Select Case reader.NodeType
                Case XmlNodeType.Element
                    writer.WriteStartElement(reader.Name)
                Case XmlNodeType.Text
                    writer.WriteString(reader.Value)
                Case XmlNodeType.XmlDeclaration
                Case XmlNodeType.ProcessingInstruction
                    writer.WriteProcessingInstruction(reader.Name, reader.Value)
                Case XmlNodeType.Comment
                    writer.WriteComment(reader.Value)
                Case XmlNodeType.EndElement
                    writer.WriteFullEndElement()
            End Select
        End While
    End Using
End Using
OutputTextBlock.Text = output.ToString()

StringBuilder output = new StringBuilder();

String xmlString =
        @"<?xml version='1.0'?>
        <!-- This is a sample XML document -->
        <Items>
          <Item>test with a child element <more/> stuff</Item>
        </Items>";
// Create an XmlReader
using (XmlReader reader = XmlReader.Create(new StringReader(xmlString)))
{
    XmlWriterSettings ws = new XmlWriterSettings();
    ws.Indent = true;
    using (XmlWriter writer = XmlWriter.Create(output, ws))
    {

        // Parse the file and display each of the nodes.
        while (reader.Read())
        {
            switch (reader.NodeType)
            {
                case XmlNodeType.Element:
                    writer.WriteStartElement(reader.Name);
                    break;
                case XmlNodeType.Text:
                    writer.WriteString(reader.Value);
                    break;
                case XmlNodeType.XmlDeclaration:
                case XmlNodeType.ProcessingInstruction:
                    writer.WriteProcessingInstruction(reader.Name, reader.Value);
                    break;
                case XmlNodeType.Comment:
                    writer.WriteComment(reader.Value);
                    break;
                case XmlNodeType.EndElement:
                    writer.WriteFullEndElement();
                    break;
            }
        }

    }
}
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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