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Package.GetPart(Uri) Method

  • Reference

Definition

Namespace:
System.IO.Packaging
Assembly:
System.IO.Packaging.dll
Assembly:
WindowsBase.dll
Package:
System.IO.Packaging v9.0.0
Source:
Package.cs
Source:
Package.cs
Source:
Package.cs
Source:
Package.cs
Source:
Package.cs

Returns the part with a given URI.

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

Parameters

partUri
Uri

The uniform resource identifier (URI) of the part to return.

Returns

PackagePart

The part with the specified partUri.

Exceptions

ArgumentNullException

partUri is null.

ArgumentException

partUri is not a valid PackagePart uniform resource identifier (URI).

InvalidOperationException

A part with the specified partUri is not in the package.

ObjectDisposedException

The package is not open (Dispose(Boolean) or Close() has been called).

IOException

The package is write-only.

Examples

The following example shows how to locate, retrieve, and read parts that are contained in a package.

// 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.

Remarks

An InvalidOperationException is thrown if a part with the specified partUri does not exist.

The PartExists method can be used to determine whether partUri references an existing part.

By default, a ZipPackage derived implementation of the abstract Package base class is provided and used. In the default operation, GetPart internally calls GetPartCore of the ZipPackage class to return a requested part from a ZIP file.

For additional information, see the Open Packaging Conventions (OPC) specification available for download at https://www.ecma-international.org/publications-and-standards/standards/ecma-376/.

Notes to Inheritors

GetPart(Uri) internally calls the derived class GetPartCore(Uri) method to actually flush the part based on the physical format implemented in the derived class.

Applies to

See also