Package.GetRelationshipsByType(String) 方法

定義

命名空間:

System.IO.Packaging

組件:

System.IO.Packaging.dll

來源:

Package.cs

傳回符合特定 RelationshipType 的所有套件層級關係的集合。

C#

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

參數

relationshipType

String

要進行比對並傳回集合的 RelationshipType。

傳回

PackageRelationshipCollection

符合指定之 relationshipType 的套件層級關係的集合。

例外狀況

ArgumentNullException

relationshipType 為 null。

ArgumentException

relationshipType 為空字串。

ObjectDisposedException

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

IOException

封裝是唯寫的。

範例

下列範例示範如何擷取為封裝定義的關聯性。

C#

// 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.

備註

GetRelationships 永遠不會傳回 null;不過，如果沒有符合指定 relationshipType之 的封裝層級關聯性，傳回的集合可能會包含零個專案。

下表顯示 Open Packaging Conventions (OPC) 規格所定義的套件層級 relationshipType URI。

套件層級關聯性	關聯性類型 URI
核心屬性	http://schemas.openxmlformats.org/package/2006/relationships/metadata/core-properties
數位簽章	http://schemas.openxmlformats.org/package/2006/relationships/digital-signature/signature
數字簽名憑證	http://schemas.openxmlformats.org/package/2006/relationships/digital-signature/certificate
數位簽名來源	http://schemas.openxmlformats.org/package/2006/relationships/digital-signature/origin
縮圖	http://schemas.openxmlformats.org/package/2006/relationships/metadata/thumbnail

如需詳細資訊，請參閱 open Packaging Conventions (OPC) specification for download at https://www.ecma-international.org/publications-and-standards/standards/ecma-376/。

適用於

另請參閱

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