XDocumentType.SystemId 屬性

定義

命名空間:
System.Xml.Linq
組件:
System.Xml.Linq.dll, System.Xml.XDocument.dll
組件:
netstandard.dll, System.Xml.XDocument.dll
組件:
System.Xml.XDocument.dll
組件:
System.Xml.Linq.dll
組件:
netstandard.dll
來源:
XDocumentType.cs
來源:
XDocumentType.cs
來源:
XDocumentType.cs
來源:
XDocumentType.cs
來源:
XDocumentType.cs

取得或設定此文件類型定義（DTD）的系統識別碼。

public:
 property System::String ^ SystemId { System::String ^ get(); void set(System::String ^ value); };
public string SystemId { get; set; }
public string? SystemId { get; set; }
member this.SystemId : string with get, set
Public Property SystemId As String

屬性值

String

String A 中包含此文件類型定義（DTD）系統識別碼的識別碼。

範例

以下範例建立一個 XML 文件，參考外部私有 DTD。 DTD 沒有內部子集。 對 XDocumentType 建構子的呼叫反映了外部私有 DTD 的使用。 它能被當 null 作內部子集。

string pubsDtd =
@"<!ELEMENT Pubs (Book+)>
<!ELEMENT Book (Title, Author)>
<!ELEMENT Title (#PCDATA)>
<!ELEMENT Author (#PCDATA)>";
File.WriteAllText("Pubs.dtd", pubsDtd);

string target = "xml-stylesheet";
string data = "href=\"mystyle.css\" title=\"Compact\" type=\"text/css\"";

XDocument doc = new XDocument(
    new XDocumentType("Pubs", null, "Pubs.dtd", null),
    new XElement("Pubs",
        new XElement("Book",
            new XElement("Title", "Artifacts of Roman Civilization"),
            new XElement("Author", "Moreno, Jordao")
        ),
        new XElement("Book",
            new XElement("Title", "Midieval Tools and Implements"),
            new XElement("Author", "Gazit, Inbar")
        )
    ),
    new XComment("This is another comment.")
);
doc.Declaration = new XDeclaration("1.0", "utf-8", "true");
doc.Save("Pubs.xml");

// Validate Pubs.xml against Pubs.dtd.
XmlReaderSettings xrs = new XmlReaderSettings();
xrs.ProhibitDtd = false;
xrs.ValidationType = ValidationType.DTD;
xrs.ConformanceLevel = ConformanceLevel.Auto;
XmlReader xr = XmlReader.Create("Pubs.xml", xrs);
XDocument doc2 = XDocument.Load(xr);

XDocumentType dt = doc2.Document.DocumentType;
Console.WriteLine("SystemId:{0}", dt.SystemId);

Dim pubsDtd As String = _
    "<!ELEMENT Pubs (Book+)>" & Environment.NewLine & _
    "<!ELEMENT Book (Title, Author)>" & Environment.NewLine & _
    "<!ELEMENT Title (#PCDATA)>" & Environment.NewLine & _
    "<!ELEMENT Author (#PCDATA)>"
File.WriteAllText("Pubs.dtd", pubsDtd)

Dim target As String = "xml-stylesheet"
Dim data As String = "href='mystyle.css' title='Compact' type='text/css'"

Dim doc As XDocument = _
    <?xml version='1.0'?>
    <Pubs>
        <Book>
            <Title>Artifacts of Roman Civilization</Title>
            <Author>Moreno, Jordao</Author>
        </Book>
        <Book>
            <Title>Midieval Tools and Implements</Title>
            <Author>Gazit, Inbar</Author>
        </Book>
    </Pubs>
    <!--This is another comment.-->

doc _
.FirstNode _
.AddBeforeSelf(New XDocumentType("Pubs", Nothing, "Pubs.dtd", Nothing))

doc.Declaration = New XDeclaration("1.0", "utf-8", "true")
doc.Save("Pubs.xml")

' Validate Pubs.xml against Pubs.dtd.
Dim xrs As XmlReaderSettings = New XmlReaderSettings()
xrs.ProhibitDtd = False
xrs.ValidationType = ValidationType.DTD
xrs.ConformanceLevel = ConformanceLevel.Auto
Dim xr As XmlReader = XmlReader.Create("Pubs.xml", xrs)
Dim doc2 As XDocument = XDocument.Load(xr)

Dim dt As XDocumentType = doc2.Document.DocumentType
Console.WriteLine("SystemId:{0}", dt.SystemId)

此範例會產生下列輸出：

SystemId:Pubs.dtd

備註

若 XML 文件使用外部私有 DTD，此屬性將包含該外部 DTD 的私有識別碼。

適用於

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