Umgestalten mit einer reinen Funktion
Aktualisiert: November 2007
Das folgende Beispiel gestaltet das vorherige Beispiel, Umgestalten mit einer Erweiterungsmethode, so um, dass es eine reine Funktion verwendet. In diesem Beispiel wird der Code, der den Text eines Absatzes ermitteln soll, in die reine statische Methode ParagraphText verschoben.
Beispiel
Dieses Beispiel verarbeitet ein WordprocessingML-Dokument, indem es die Absatzknoten aus einem WordprocessingML-Dokument abruft. Außerdem ermittelt es für jeden Absatz die verwendete Formatvorlage. Das Beispiel baut auf den vorherigen Beispielen dieses Lernprogramms auf. Der umgestaltete Code wird im Code durch entsprechende Kommentare gekennzeichnet.
Anweisungen zum Erstellen des Quelldokuments für dieses Beispiel finden Sie unter Erstellen des Office Open XML-Quelldokuments.
Dieses Beispiel verwendet Klassen aus der WindowsBase-Assembly. Außerdem werden Typen im System.IO.Packaging-Namespace verwendet.
public static class LocalExtensions
{
public static string StringConcatenate(this IEnumerable<string> source)
{
StringBuilder sb = new StringBuilder();
foreach (string s in source)
sb.Append(s);
return sb.ToString();
}
public static string StringConcatenate<T>(this IEnumerable<T> source,
Func<T, string> func)
{
StringBuilder sb = new StringBuilder();
foreach (T item in source)
sb.Append(func(item));
return sb.ToString();
}
public static string StringConcatenate(this IEnumerable<string> source, string separator)
{
StringBuilder sb = new StringBuilder();
foreach (string s in source)
sb.Append(s).Append(separator);
return sb.ToString();
}
public static string StringConcatenate<T>(this IEnumerable<T> source,
Func<T, string> func, string separator)
{
StringBuilder sb = new StringBuilder();
foreach (T item in source)
sb.Append(func(item)).Append(separator);
return sb.ToString();
}
}
class Program
{
// This is a new method that assembles the paragraph text.
public static string ParagraphText(XElement e)
{
XNamespace w = e.Name.Namespace;
return e
.Elements(w + "r")
.Elements(w + "t")
.StringConcatenate(element => (string)element);
}
static void Main(string[] args)
{
const string fileName = "SampleDoc.docx";
const string documentRelationshipType =
"https://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument";
const string stylesRelationshipType =
"https://schemas.openxmlformats.org/officeDocument/2006/relationships/styles";
const string wordmlNamespace =
"https://schemas.openxmlformats.org/wordprocessingml/2006/main";
XNamespace w = wordmlNamespace;
XDocument xDoc = null;
XDocument styleDoc = null;
using (Package wdPackage = Package.Open(fileName, FileMode.Open, FileAccess.Read))
{
PackageRelationship docPackageRelationship =
wdPackage.GetRelationshipsByType(documentRelationshipType).FirstOrDefault();
if (docPackageRelationship != null)
{
Uri documentUri = PackUriHelper.ResolvePartUri(new Uri("/", UriKind.Relative),
docPackageRelationship.TargetUri);
PackagePart documentPart = wdPackage.GetPart(documentUri);
// Load the document XML in the part into an XDocument instance.
xDoc = XDocument.Load(XmlReader.Create(documentPart.GetStream()));
// Find the styles part. There will only be one.
PackageRelationship styleRelation =
documentPart.GetRelationshipsByType(stylesRelationshipType).FirstOrDefault();
if (styleRelation != null)
{
Uri styleUri = PackUriHelper.ResolvePartUri(documentUri,
styleRelation.TargetUri);
PackagePart stylePart = wdPackage.GetPart(styleUri);
// Load the style XML in the part into an XDocument instance.
styleDoc = XDocument.Load(XmlReader.Create(stylePart.GetStream()));
}
}
}
string defaultStyle =
(string)(
from style in styleDoc.Root.Elements(w + "style")
where (string)style.Attribute(w + "type") == "paragraph" &&
(string)style.Attribute(w + "default") == "1"
select style
).First().Attribute(w + "styleId");
// Find all paragraphs in the document.
var paragraphs =
from para in xDoc
.Root
.Element(w + "body")
.Descendants(w + "p")
let styleNode = para
.Elements(w + "pPr")
.Elements(w + "pStyle")
.FirstOrDefault()
select new
{
ParagraphNode = para,
StyleName = styleNode != null ?
(string)styleNode.Attribute(w + "val") :
defaultStyle
};
// Retrieve the text of each paragraph.
var paraWithText =
from para in paragraphs
select new
{
ParagraphNode = para.ParagraphNode,
StyleName = para.StyleName,
Text = ParagraphText(para.ParagraphNode)
};
foreach (var p in paraWithText)
Console.WriteLine("StyleName:{0} >{1}<", p.StyleName, p.Text);
}
}
[vb]
Imports <xmlns:w="https://schemas.openxmlformats.org/wordprocessingml/2006/main">
Module Module1
<System.Runtime.CompilerServices.Extension()> _
Public Function StringConcatenate(ByVal source As IEnumerable(Of String)) As String
Dim sb As StringBuilder = New StringBuilder()
For Each s As String In source
sb.Append(s)
Next
Return sb.ToString()
End Function
<System.Runtime.CompilerServices.Extension()> _
Public Function StringConcatenate(Of T)(ByVal source As IEnumerable(Of T), _
ByVal func As Func(Of T, String)) As String
Dim sb As StringBuilder = New StringBuilder()
For Each item As T In source
sb.Append(func(item))
Next
Return sb.ToString()
End Function
<System.Runtime.CompilerServices.Extension()> _
Public Function StringConcatenate(Of T)(ByVal source As IEnumerable(Of T), _
ByVal separator As String) As String
Dim sb As StringBuilder = New StringBuilder()
For Each s As T In source
sb.Append(s).Append(separator)
Next
Return sb.ToString()
End Function
<System.Runtime.CompilerServices.Extension()> _
Public Function StringConcatenate(Of T)(ByVal source As IEnumerable(Of T), _
ByVal func As Func(Of T, String), ByVal separator As String) As String
Dim sb As StringBuilder = New StringBuilder()
For Each item As T In source
sb.Append(func(item)).Append(separator)
Next
Return sb.ToString()
End Function
' This is a new method that assembles the paragraph text.
Public Function ParagraphText(ByVal e As XElement) As String
Dim w As XNamespace = e.Name.Namespace
Return (e.<w:r>.<w:t>).StringConcatenate(Function(element) CStr(element))
End Function
' Following function is required because VB does not support short circuit evaluation
Private Function GetStyleOfParagraph(ByVal styleNode As XElement, _
ByVal defaultStyle As String) As String
If (styleNode Is Nothing) Then
Return defaultStyle
Else
Return styleNode.@w:val
End If
End Function
Sub Main()
Dim fileName = "SampleDoc.docx"
Dim documentRelationshipType = _
"https://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument"
Dim stylesRelationshipType = _
"https://schemas.openxmlformats.org/officeDocument/2006/relationships/styles"
Dim wordmlNamespace = _
"https://schemas.openxmlformats.org/wordprocessingml/2006/main"
Dim xDoc As XDocument = Nothing
Dim styleDoc As XDocument = Nothing
Using wdPackage As Package = Package.Open(fileName, FileMode.Open, FileAccess.Read)
Dim docPackageRelationship As PackageRelationship = _
wdPackage.GetRelationshipsByType(documentRelationshipType).FirstOrDefault()
If (docPackageRelationship IsNot Nothing) Then
Dim documentUri As Uri = PackUriHelper.ResolvePartUri(New Uri("/", UriKind.Relative), _
docPackageRelationship.TargetUri)
Dim documentPart As PackagePart = wdPackage.GetPart(documentUri)
' Load the document XML in the part into an XDocument instance.
xDoc = XDocument.Load(XmlReader.Create(documentPart.GetStream()))
' Find the styles part. There will only be one.
Dim styleRelation As PackageRelationship = _
documentPart.GetRelationshipsByType(stylesRelationshipType).FirstOrDefault()
If (Not (styleRelation Is Nothing)) Then
Dim styleUri As Uri = _
PackUriHelper.ResolvePartUri(documentUri, styleRelation.TargetUri)
Dim stylePart As PackagePart = wdPackage.GetPart(styleUri)
' Load the style XML in the part into an XDocument instance.
styleDoc = XDocument.Load(XmlReader.Create(stylePart.GetStream()))
End If
End If
End Using
Dim defaultStyle As String = _
( _
From style In styleDoc.Root.<w:style> _
Where style.@w:type = "paragraph" And _
style.@w:default = "1" _
Select style _
).First().@w:styleId
' Find all paragraphs in the document.
Dim paragraphs = _
From para In xDoc.Root.<w:body>...<w:p> _
Let styleNode As XElement = para.<w:pPr>.<w:pStyle>.FirstOrDefault _
Select New With { _
.ParagraphNode = para, _
.StyleName = GetStyleOfParagraph(styleNode, defaultStyle) _
}
' Retrieve the text of each paragraph.
Dim paraWithText = _
From para In paragraphs _
Select New With { _
.ParagraphNode = para.ParagraphNode, _
.StyleName = para.StyleName, _
.Text = ParagraphText(para.ParagraphNode) _
}
For Each p In paraWithText
Console.WriteLine("StyleName:{0} >{1}<", p.StyleName, p.Text)
Next
End Sub
End Module
Dieses Beispiel erzeugt dieselbe Ausgabe wie vor der Umgestaltung:
StyleName:Heading1 >Parsing WordprocessingML with LINQ to XML<
StyleName:Normal ><
StyleName:Normal >The following example prints to the console.<
StyleName:Normal ><
StyleName:Code >using System;<
StyleName:Code ><
StyleName:Code >class Program {<
StyleName:Code > public static void (string[] args) {<
StyleName:Code > Console.WriteLine("Hello World");<
StyleName:Code > }<
StyleName:Code >}<
StyleName:Normal ><
StyleName:Normal >This example produces the following output:<
StyleName:Normal ><
StyleName:Code >Hello World<
Nächste Schritte
Im nächsten Beispiel wird gezeigt, wie Sie XML in eine andere Form projizieren können:
Siehe auch
Aufgaben
Umgestalten mit einer Erweiterungsmethode
Konzepte
Lernprogramm: Bearbeiten des Inhalts eines WordprocessingML-Dokuments