Package Class

Definition

Namespace:

System.IO.Packaging

Assembly:

System.IO.Packaging.dll

Represents a container that can store multiple data objects.

public ref class Package abstract : IDisposable

public abstract class Package : IDisposable

type Package = class
    interface IDisposable

Public MustInherit Class Package
Implements IDisposable

Inheritance

Object

Package

Derived

System.IO.Packaging.ZipPackage

Examples

The following example shows the basic steps for creating a Package. In this example, a package is created to contain a document together with a graphic image that is displayed as part of the document. (This is similar to the case in which an HTML file has an <IMG> tag that references an external image file.) Two PackageRelationship elements are also included in the package. The first, a "package-level" relationship, defines the document part as the package's root element. A second, "part-level" relationship defines the association between the document part (the "source" of the part-level relationship) and its use of the image part (the "target" of the part-level relationship).

//  -------------------------- CreatePackage --------------------------
/// <summary>
///   Creates a package zip file containing specified
///   content and resource files.</summary>
private static void CreatePackage()
{
    // Convert system path and file names to Part URIs. In this example
    // Uri partUriDocument /* /Content/Document.xml */ =
    //     PackUriHelper.CreatePartUri(
    //         new Uri("Content\Document.xml", UriKind.Relative));
    // Uri partUriResource /* /Resources/Image1.jpg */ =
    //     PackUriHelper.CreatePartUri(
    //         new Uri("Resources\Image1.jpg", UriKind.Relative));
    Uri partUriDocument = PackUriHelper.CreatePartUri(
                              new Uri(documentPath, UriKind.Relative));
    Uri partUriResource = PackUriHelper.CreatePartUri(
                              new Uri(resourcePath, UriKind.Relative));

    // Create the Package
    // (If the package file already exists, FileMode.Create will
    //  automatically delete it first before creating a new one.
    //  The 'using' statement insures that 'package' is
    //  closed and disposed when it goes out of scope.)
    using (Package package =
        Package.Open(packagePath, FileMode.Create))
    {
        // Add the Document part to the Package
        PackagePart packagePartDocument =
            package.CreatePart(partUriDocument,
                           System.Net.Mime.MediaTypeNames.Text.Xml);

        // Copy the data to the Document Part
        using (FileStream fileStream = new FileStream(
               documentPath, FileMode.Open, FileAccess.Read))
        {
            CopyStream(fileStream, packagePartDocument.GetStream());
        }// end:using(fileStream) - Close and dispose fileStream.

        // Add a Package Relationship to the Document Part
        package.CreateRelationship(packagePartDocument.Uri,
                                   TargetMode.Internal,
                                   PackageRelationshipType);

        // Add a Resource Part to the Package
        PackagePart packagePartResource =
            package.CreatePart(partUriResource,
                           System.Net.Mime.MediaTypeNames.Image.Jpeg);

        // Copy the data to the Resource Part
        using (FileStream fileStream = new FileStream(
               resourcePath, FileMode.Open, FileAccess.Read))
        {
            CopyStream(fileStream, packagePartResource.GetStream());
        }// end:using(fileStream) - Close and dispose fileStream.

        // Add Relationship from the Document part to the Resource part
        packagePartDocument.CreateRelationship(
                                new Uri(@"../resources/image1.jpg",
                                UriKind.Relative),
                                TargetMode.Internal,
                                ResourceRelationshipType);
    }// end:using (Package package) - Close and dispose package.
}// end:CreatePackage()

//  --------------------------- CopyStream ---------------------------
/// <summary>
///   Copies data from a source stream to a target stream.</summary>
/// <param name="source">
///   The source stream to copy from.</param>
/// <param name="target">
///   The destination stream to copy to.</param>
private static void CopyStream(Stream source, Stream target)
{
    const int bufSize = 0x1000;
    byte[] buf = new byte[bufSize];
    int bytesRead = 0;
    while ((bytesRead = source.Read(buf, 0, bufSize)) > 0)
        target.Write(buf, 0, bytesRead);
}// end:CopyStream()

'  -------------------------- CreatePackage --------------------------
''' <summary>
'''   Creates a package zip file containing specified
'''   content and resource files.</summary>
Private Shared Sub CreatePackage()
    ' Convert system path and file names to Part URIs. In this example
    ' Dim partUriDocument as Uri /* /Content/Document.xml */ =
    '     PackUriHelper.CreatePartUri(
    '         New Uri("Content\Document.xml", UriKind.Relative))
    ' Dim partUriResource as Uri /* /Resources/Image1.jpg */ =
    '     PackUriHelper.CreatePartUri(
    '         New Uri("Resources\Image1.jpg", UriKind.Relative))
    Dim partUriDocument As Uri = PackUriHelper.CreatePartUri(New Uri(documentPath, UriKind.Relative))
    Dim partUriResource As Uri = PackUriHelper.CreatePartUri(New Uri(resourcePath, UriKind.Relative))

    ' Create the Package
    ' (If the package file already exists, FileMode.Create will
    '  automatically delete it first before creating a new one.
    '  The 'using' statement insures that 'package' is
    '  closed and disposed when it goes out of scope.)
    Using package As Package = Package.Open(packagePath, FileMode.Create)
        ' Add the Document part to the Package
        Dim packagePartDocument As PackagePart = package.CreatePart(partUriDocument, System.Net.Mime.MediaTypeNames.Text.Xml)

        ' Copy the data to the Document Part
        Using fileStream As New FileStream(documentPath, FileMode.Open, FileAccess.Read)
            CopyStream(fileStream, packagePartDocument.GetStream())
        End Using ' end:using(fileStream) - Close and dispose fileStream.

        ' Add a Package Relationship to the Document Part
        package.CreateRelationship(packagePartDocument.Uri, TargetMode.Internal, PackageRelationshipType)

        ' Add a Resource Part to the Package
        Dim packagePartResource As PackagePart = package.CreatePart(partUriResource, System.Net.Mime.MediaTypeNames.Image.Jpeg)

        ' Copy the data to the Resource Part
        Using fileStream As New FileStream(resourcePath, FileMode.Open, FileAccess.Read)
            CopyStream(fileStream, packagePartResource.GetStream())
        End Using ' end:using(fileStream) - Close and dispose fileStream.

        ' Add Relationship from the Document part to the Resource part
        packagePartDocument.CreateRelationship(New Uri("../resources/image1.jpg", UriKind.Relative), TargetMode.Internal, ResourceRelationshipType)

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

End Sub


'  --------------------------- CopyStream ---------------------------
''' <summary>
'''   Copies data from a source stream to a target stream.</summary>
''' <param name="source">
'''   The source stream to copy from.</param>
''' <param name="target">
'''   The destination stream to copy to.</param>
Private Shared Sub CopyStream(ByVal source As Stream, ByVal target As Stream)
    Const bufSize As Integer = &H1000
    Dim buf(bufSize - 1) As Byte
    Dim bytesRead As Integer = 0
    bytesRead = source.Read(buf, 0, bufSize)
    Do While bytesRead > 0
        target.Write(buf, 0, bytesRead)
        bytesRead = source.Read(buf, 0, bufSize)
    Loop
End Sub

Remarks

Package is an abstract class that can be used to organize objects into a single entity of a defined physical format for portability and efficient access.

A ZIP file is the primary physical format for the Package. Other Package implementations might use other physical formats such as an XML document, a database, or Web service.

Like a file system, items contained in a Package are referenced in a hierarchical organization of folders and files.

Although Package itself is an abstract class, the ZipPackage derived class is used as default by the Open method.

A PackagePart ("part") is the abstract class that represents an object that is stored in a Package.

A PackageRelationship ("relationship") defines an association between a source Package or PackagePart and a target object. A PackageRelationship can be one of two types, each of which can be one of two forms:

• A package-level relationship (created by the Package.CreateRelationship method) relates a Package to either:

  • A target part in the package.
  • A target resource outside the package.

• A part-level relationship (created by the PackagePart.CreateRelationship method) relates a source PackagePart to either:

  • Another target part in the package.
  • A target resource outside the package.

The relationship's source Package or source PackagePart is considered the "owner" of the relationship. When the source object is deleted, all the relationships owned by the source object are also deleted. The process of creating or deleting a relationship does not physically change either the source or target objects in any way.

A PackageDigitalSignature ("digital signature") is a composition of parts and relationships representing a digital signature included with a Package. The digital signature identifies the originator and validates that the signed parts and relationships contained in the Package have not been modified.

Packages also support Digital Rights Management (DRM) which allows content elements in a Package to be encrypted with specific access rights granted to authorized users.

Based on the Package architecture, an XpsDocument is a package type designed for storing documents based on the open XML Paper Specification (XPS).

.NET Framework uses packages to store content, resources, and relationships for pages and documents using a standard ZIP file by default. As with any ZIP file, your application can use the System.IO.Packaging classes to store and optionally protect any type or number of data files in a single efficient-to-access container.

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

Constructors

Package(FileAccess)

Initializes a new instance of the Package class that uses a given FileAccess.

Properties

FileOpenAccess	Gets the file access setting for the package.
PackageProperties	Gets the core properties of the package.

Methods

Close()	Saves and closes the package plus all underlying part streams.
CreatePart(Uri, String, CompressionOption)	Creates a new part with a given URI, content type, and compression option.
CreatePart(Uri, String)	Creates a new uncompressed part with a given URI and content type.
CreatePartCore(Uri, String, CompressionOption)	When overridden in a derived class, creates a new part in the package.
CreateRelationship(Uri, TargetMode, String, String)	Creates a package-level relationship to a part with a given URI, target mode, relationship type, and identifier (ID).
CreateRelationship(Uri, TargetMode, String)	Creates a package-level relationship to a part with a given URI, target mode, and relationship type.
DeletePart(Uri)	Deletes a part with a given URI from the package.
DeletePartCore(Uri)	When overridden in a derived class, deletes a part with a given URI.
DeleteRelationship(String)	Deletes a package-level relationship.
Dispose(Boolean)	Flushes and saves the content of all parts and relationships, closes the package, and releases all resources.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
Flush()	Saves the contents of all parts and relationships that are contained in the package.
FlushCore()	When overridden in a derived class, saves the content of all parts and relationships to the derived class store.
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetPart(Uri)	Returns the part with a given URI.
GetPartCore(Uri)	When overridden in a derived class, returns the part addressed by a given URI.
GetParts()	Returns a collection of all the parts in the package.
GetPartsCore()	When overridden in a derived class, returns an array of all the parts in the package.
GetRelationship(String)	Returns the package-level relationship with a given identifier.
GetRelationships()	Returns a collection of all the package-level relationships.
GetRelationshipsByType(String)	Returns a collection of all the package-level relationships that match a given RelationshipType.
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
Open(Stream, FileMode, FileAccess)	Opens a package with a given IO stream, file mode, and file access setting.
Open(Stream, FileMode)	Opens a package with a given IO stream and file mode.
Open(Stream)	Opens a package on a given IO stream.
Open(String, FileMode, FileAccess, FileShare)	Opens a package at a given path using a given file mode, file access, and file share setting.
Open(String, FileMode, FileAccess)	Opens a package at a given path using a given file mode and file access setting.
Open(String, FileMode)	Opens a package at a given path using a given file mode.
Open(String)	Opens a package at a given path and file name.
PartExists(Uri)	Indicates whether a part with a given URI is in the package.
RelationshipExists(String)	Indicates whether a package-level relationship with a given ID is contained in the package.
ToString()	Returns a string that represents the current object. (Inherited from Object)

Explicit Interface Implementations

IDisposable.Dispose()

This member supports the Windows Presentation Foundation (WPF) infrastructure and is not intended for application use. Use the type-safe Dispose(Boolean) method instead.

See also

• PackagePart
• XpsDocument
• Open Packaging Conventions (OPC) Specification