搭配使用 DTD 與 XmlReader 進行驗證
更新： November 2007
文件類型定義 (DTD) 驗證是使用全球資訊網協會 (W3C) 可延伸標記語言 (XML) 1.0 版建議事項中定義的有效性條件約束進行實作。DTD 使用正式文法描述相容 XML 文件的結構和語法；它們指定可用於 XML 文件的內容和值。
若要執行 DTD 驗證，XmlReader 會使用在 XML 文件之 DOCTYPE 宣告中所定義的 DTD。DOCTYPE 宣告可以指向內嵌 DTD，也可以是外部 DTD 檔案的參考。
將 XmlReaderSettings.ProhibitDtd 屬性設為 false。
將 XmlReaderSettings.ValidationType 屬性設為 ValidationType.DTD。
如果 DTD 是儲存在需要驗證之網路資源上的外部檔案，請將具有必要認證的 XmlResolver 物件傳遞至 Create 方法。
範例
下列範例使用 DTD 檔案驗證 XML 檔案。
Imports System
Imports System.Xml
Imports System.Xml.Schema
Imports System.IO
public class Sample
public shared sub Main()
' Set the validation settings.
Dim settings as XmlReaderSettings = new XmlReaderSettings()
settings.ProhibitDtd = false
settings.ValidationType = ValidationType.DTD
AddHandler settings.ValidationEventHandler, AddressOf ValidationCallBack
' Create the XmlReader object.
Dim reader as XmlReader = XmlReader.Create("itemDTD.xml", settings)
' Parse the file.
while reader.Read()
end while
end sub
' Display any validation errors.
private shared sub ValidationCallBack(sender as object, e as ValidationEventArgs)
Console.WriteLine("Validation Error: {0}", e.Message)
end sub
end class
using System;
using System.Xml;
using System.Xml.Schema;
using System.IO;
public class Sample {
public static void Main() {
// Set the validation settings.
XmlReaderSettings settings = new XmlReaderSettings();
settings.ProhibitDtd = false;
settings.ValidationType = ValidationType.DTD;
settings.ValidationEventHandler += new ValidationEventHandler (ValidationCallBack);
// Create the XmlReader object.
XmlReader reader = XmlReader.Create("itemDTD.xml", settings);
// Parse the file.
while (reader.Read());
}
// Display any validation errors.
private static void ValidationCallBack(object sender, ValidationEventArgs e) {
Console.WriteLine("Validation Error: {0}", e.Message);
}
}
#using <System.Xml.dll>
using namespace System;
using namespace System::Xml;
using namespace System::Xml::Schema;
using namespace System::IO;
// Display any validation errors.
static void ValidationCallBack( Object^ /*sender*/, ValidationEventArgs^ e )
{
Console::WriteLine( L"Validation Error: {0}", e->Message );
}
int main()
{
// Set the validation settings.
XmlReaderSettings^ settings = gcnew XmlReaderSettings;
settings->ProhibitDtd = false;
settings->ValidationType = ValidationType::DTD;
settings->ValidationEventHandler += gcnew ValidationEventHandler( ValidationCallBack );
// Create the XmlReader object.
XmlReader^ reader = XmlReader::Create( L"itemDTD.xml", settings );
// Parse the file.
while ( reader->Read() )
;
return 1;
}
輸入
該範例使用 itemDTD.xml 檔案做為輸入。
<!--XML file using a DTD-->
<!DOCTYPE store [
<!ELEMENT store (item)*>
<!ELEMENT item (name,dept,price)>
<!ATTLIST item type CDATA #REQUIRED>
<!ELEMENT name (#PCDATA)>
<!ELEMENT price (#PCDATA)>]>
<store>
<item type="supplies" ISBN="2-3631-4">
<name>paint</name>
<price>16.95</price>
</item>
</store>