Package.GetPart(Uri) 方法

定義

命名空間:

System.IO.Packaging

組件:

System.IO.Packaging.dll

套件:

System.IO.Packaging v8.0.0

來源:

Package.cs

傳回具有特定 URI 的組件。

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

參數

partUri

Uri

要傳回之組件的統一資源識別項 (URI)。

傳回

PackagePart

具有指定之 partUri 的組件。

例外狀況

ArgumentNullException

partUri 為 null。

ArgumentException

partUri 不是有效的 PackagePart 統一資源識別項 (URI)。

InvalidOperationException

具有指定之 partUri 的組件不在套件內。

ObjectDisposedException

套件沒有開啟 (已呼叫 Dispose(Boolean) 或 Close())。

IOException

封裝是唯寫的。

範例

下列範例示範如何尋找、擷取和讀取套件中包含的元件。 如需完整的範例，請參閱 閱讀套件範例。

// 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.

備註

InvalidOperationException如果具有指定partUri之 的元件不存在，則會擲回 。

PartExists方法可用來判斷是否partUri參考現有的元件。

根據預設， ZipPackage 會提供及使用抽象 Package 基類的衍生實作。 在預設作業中， GetPart 在內部呼叫 GetPartCoreZipPackage 類別，以從 ZIP 檔案傳回要求的元件。

如需詳細資訊，請參閱可在 下載 https://www.ecma-international.org/publications-and-standards/standards/ecma-376/的開放封裝慣例 (OPC) 規格。

給繼承者的注意事項

GetPart(Uri) 在內部呼叫衍生類別 GetPartCore(Uri) 方法，根據衍生類別中實作的實體格式，實際排清元件。

另請參閱

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