XDocumentType.SystemId 屬性

定義

命名空間:

System.Xml.Linq

組件:

System.Xml.XDocument.dll

組件:

System.Xml.Linq.dll

組件:

netstandard.dll

取得或設定這個文件類型定義 (DTD) 的系統識別項。

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，包含這個文件類型定義 (DTD) 的系統識別項。

範例

下列範例會建立參考外部私人 DTD 的 XML 檔。 DTD 沒有內部子集。 對建 XDocumentType 構函式的呼叫會反映外部私人 DTD 的使用。 它會針對內部子集傳遞 null 。

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)  

這個範例會產生下列輸出：

SystemId:Pubs.dtd  

備註

如果 XML 檔使用外部私人 DTD，此屬性將包含外部 DTD 的私人識別碼。

另請參閱

• LINQ to XML 概觀