Package.GetPart(Uri) 方法

定义

返回具有给定 URI 的部件。

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

参数

partUri
Uri

要返回的部件的统一资源标识符 (URI)。

返回

具有指定 partUri 的部件。

例外

partUrinull

partUri 不是有效的 PackagePart 统一资源标识符 (URI)。

包中不存在具有指定 partUri 的部件。

包未打开(已调用了 Dispose(Boolean)Close())。

包是只写的。

示例

以下示例演示如何查找、检索和读取包中包含的部件。

// 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

InvalidOperationException如果具有指定 partUri 的部件不存在,则会引发 。

方法 PartExists 可用于确定是否 partUri 引用现有部件。

默认情况下, ZipPackage 提供并使用抽象 Package 基类的派生实现。 在默认操作中, GetPart 在内部调用 GetPartCoreZipPackage 类以从 ZIP 文件返回请求的部件。

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/

继承者说明

GetPart(Uri) 在内部调用派生类方法,根据派生类 GetPartCore(Uri) 中实现的物理格式实际刷新部件。

适用于

另请参阅