Package.GetRelationshipsByType(String) 方法

定义

命名空间:

System.IO.Packaging

程序集:

System.IO.Packaging.dll

包:

System.IO.Packaging v8.0.0

Source:

Package.cs

返回与给定的 RelationshipType 匹配的所有包级别关系的集合。

public:
 System::IO::Packaging::PackageRelationshipCollection ^ GetRelationshipsByType(System::String ^ relationshipType);

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

member this.GetRelationshipsByType : string -> System.IO.Packaging.PackageRelationshipCollection

Public Function GetRelationshipsByType (relationshipType As String) As PackageRelationshipCollection

参数

relationshipType

String

在集合中匹配和返回的 RelationshipType。

返回

PackageRelationshipCollection

与指定的 relationshipType 匹配的包级别关系的集合。

例外

ArgumentNullException

relationshipType 为 null。

ArgumentException

relationshipType 是一个空字符串。

ObjectDisposedException

包未打开（已调用了 Dispose(Boolean) 或 Close()）。

IOException

包是只写的。

示例

以下示例演示如何检索已为包定义的关系。 有关完整示例，请参阅 读取包示例。

// 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.

注解

GetRelationships 永远不会返回 null;但是，如果没有与指定的 relationshipType匹配的包级关系，则返回的集合可能包含零个元素。

下表显示了开放打包约定 (OPC) 规范定义的包级 relationshipType URI。

包级关系	关系类型 URI
核心属性	http://schemas.openxmlformats.org/package/2006/relationships/metadata/core-properties
数字签名	http://schemas.openxmlformats.org/package/2006/relationships/digital-signature/signature
数字签名证书	http://schemas.openxmlformats.org/package/2006/relationships/digital-signature/certificate
数字签名源	http://schemas.openxmlformats.org/package/2006/relationships/digital-signature/origin
缩略图	http://schemas.openxmlformats.org/package/2006/relationships/metadata/thumbnail

有关其他信息，请参阅开放打包约定 (OPC) 规范，可从 下载 https://www.ecma-international.org/publications-and-standards/standards/ecma-376/。

另请参阅

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