Package.GetPart(Uri) Metodo

public:
 System::IO::Packaging::PackagePart ^ GetPart(Uri ^ partUri);

public System.IO.Packaging.PackagePart GetPart (Uri partUri);

member this.GetPart : Uri -> System.IO.Packaging.PackagePart

Public Function GetPart (partUri As Uri) As PackagePart

Parametri

Restituisce

La parte con partUri specificato.

Eccezioni

Esempio

Nell'esempio seguente viene illustrato come individuare, recuperare e leggere parti contenute in un 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

Viene InvalidOperationException generata un'eccezione se una parte con l'oggetto specificato partUri non esiste.

Il PartExists metodo può essere utilizzato per determinare se partUri fa riferimento a una parte esistente.

Per impostazione predefinita, viene fornita e utilizzata un'implementazione ZipPackage derivata della classe base astratta Package . Nell'operazione predefinita chiama GetPartGetPartCore internamente la ZipPackage classe per restituire una parte richiesta da un file ZIP.

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

Note per gli eredi

GetPart(Uri) internamente chiama il metodo della classe GetPartCore(Uri) derivata per scaricare effettivamente la parte in base al formato fisico implementato nella classe derivata.

Si applica a

Vedi anche

• GetParts()
• PartExists(Uri)
• CreatePartUri(Uri)
• GetPartUri(Uri)
• ResolvePartUri(Uri, Uri)