Package.GetRelationshipsByType(String) Metodo

Definizione

Spazio dei nomi:

System.IO.Packaging

Assembly:

System.IO.Packaging.dll

Pacchetto:

System.IO.Packaging v8.0.0

Origine:

Package.cs

Restituisce un insieme di tutte le relazioni a livello di pacchetto che corrispondono a RelationshipType specificato.

public:
 System::IO::Packaging::PackageRelationshipCollection ^ GetRelationshipsByType(System::String ^ relationshipType);

public System.IO.Packaging.PackageRelationshipCollection GetRelationshipsByType (string relationshipType);

member this.GetRelationshipsByType : string -> System.IO.Packaging.PackageRelationshipCollection

Public Function GetRelationshipsByType (relationshipType As String) As PackageRelationshipCollection

Parametri

relationshipType

String

Oggetto RelationshipType al quale corrispondere e da restituire nella raccolta.

Restituisce

PackageRelationshipCollection

Un insieme di relazioni a livello di pacchetto che corrispondono a relationshipType specificato.

Eccezioni

ArgumentNullException

relationshipType è null.

ArgumentException

Il parametro relationshipType è una stringa vuota.

ObjectDisposedException

Il pacchetto non è aperto (Dispose(Boolean) o Close() è stato chiamato).

IOException

Il pacchetto è di sola scrittura.

Esempio

Nell'esempio seguente viene illustrato come recuperare le relazioni definite per il pacchetto. Per l'esempio completo, vedere Lettura di un esempio di pacchetto.

// Open the Package.
// ('using' statement insures that 'package' is
//  closed and disposed when it goes out of scope.)
using (Package package =
    Package.Open(packagePath, FileMode.Open, FileAccess.Read))
{
    PackagePart documentPart = null;
    PackagePart resourcePart = null;

    // Get the Package Relationships and look for
    //   the Document part based on the RelationshipType
    Uri uriDocumentTarget = null;
    foreach (PackageRelationship relationship in
        package.GetRelationshipsByType(PackageRelationshipType))
    {
        // Resolve the Relationship Target Uri
        //   so the Document Part can be retrieved.
        uriDocumentTarget = PackUriHelper.ResolvePartUri(
            new Uri("/", UriKind.Relative), relationship.TargetUri);

        // Open the Document Part, write the contents to a file.
        documentPart = package.GetPart(uriDocumentTarget);
        ExtractPart(documentPart, targetDirectory);
    }

    // Get the Document part's Relationships,
    //   and look for required resources.
    Uri uriResourceTarget = null;
    foreach (PackageRelationship relationship in
        documentPart.GetRelationshipsByType(
                                ResourceRelationshipType))
    {
        // Resolve the Relationship Target Uri
        //   so the Resource Part can be retrieved.
        uriResourceTarget = PackUriHelper.ResolvePartUri(
            documentPart.Uri, relationship.TargetUri);

        // Open the Resource Part and write the contents to a file.
        resourcePart = package.GetPart(uriResourceTarget);
        ExtractPart(resourcePart, targetDirectory);
    }
}// end:using(Package package) - Close & dispose package.

' Open the Package.
' ('using' statement insures that 'package' is
'  closed and disposed when it goes out of scope.)
Using package As Package = Package.Open(packagePath, FileMode.Open, FileAccess.Read)
    Dim documentPart As PackagePart = Nothing
    Dim resourcePart As PackagePart = Nothing

    ' Get the Package Relationships and look for
    '   the Document part based on the RelationshipType
    Dim uriDocumentTarget As Uri = Nothing
    For Each relationship As PackageRelationship In package.GetRelationshipsByType(PackageRelationshipType)
        ' Resolve the Relationship Target Uri
        '   so the Document Part can be retrieved.
        uriDocumentTarget = PackUriHelper.ResolvePartUri(New Uri("/", UriKind.Relative), relationship.TargetUri)

        ' Open the Document Part, write the contents to a file.
        documentPart = package.GetPart(uriDocumentTarget)
        ExtractPart(documentPart, targetDirectory)
    Next relationship

    ' Get the Document part's Relationships,
    '   and look for required resources.
    Dim uriResourceTarget As Uri = Nothing
    For Each relationship As PackageRelationship In documentPart.GetRelationshipsByType(ResourceRelationshipType)
        ' Resolve the Relationship Target Uri
        '   so the Resource Part can be retrieved.
        uriResourceTarget = PackUriHelper.ResolvePartUri(documentPart.Uri, relationship.TargetUri)

        ' Open the Resource Part and write the contents to a file.
        resourcePart = package.GetPart(uriResourceTarget)
        ExtractPart(resourcePart, targetDirectory)
    Next relationship

End Using ' end:using(Package package) - Close & dispose package.

Commenti

GetRelationships non restituirà nullmai ; tuttavia la raccolta restituita potrebbe contenere zero elementi se non sono presenti relazioni a livello di pacchetto che corrispondono all'oggetto specificato relationshipType.

Nella tabella seguente vengono illustrati gli URI a livello relationshipType di pacchetto definiti dalla specifica OPC (Open Packaging Conventions).

Relazione a livello di pacchetto	URI del tipo di relazione
Proprietà principali	http://schemas.openxmlformats.org/package/2006/relationships/metadata/core-properties
Firma digitale	http://schemas.openxmlformats.org/package/2006/relationships/digital-signature/signature
Certificato firma digitale	http://schemas.openxmlformats.org/package/2006/relationships/digital-signature/certificate
Origine firma digitale	http://schemas.openxmlformats.org/package/2006/relationships/digital-signature/origin
Anteprima	http://schemas.openxmlformats.org/package/2006/relationships/metadata/thumbnail

Per altre informazioni, vedere la specifica Open Packaging Conventions (OPC) disponibile per il download in https://www.ecma-international.org/publications-and-standards/standards/ecma-376/.

Vedi anche

• GetRelationship(String)
• GetRelationships()
• CreateRelationship(Uri, TargetMode, String)
• DeleteRelationship(String)