使用 C++ 从 EPS 文件获取 XMP 元数据

为了从 EPS 文件中提取 XMP 元数据，需要执行以下几个步骤：

1. 为输入的 EPS 文件初始化输入流。
2. 从先前创建的输入流创建 PsDocument 实例。
3. 从 PsDocument 获取 XmpMetadata 实例。如果给定的 EPS 文件不包含 XMP 元数据，则将创建新的实例，并使用 PS 元数据注释中的值填充该实例并返回给您。
4. 现在您可以查看元数据字段的值。

以下代码片段展示了如何在 C++ 中从 EPS 文件中提取 XMP 元数据：

// For complete examples and data files, please go to https://github.com/aspose-page/Aspose.Page-for-C
// The path to the documents directory.
System::String dataDir = RunExamples::GetDataDir_WorkingWithXMPMetadataInEPS();
// Initialize EPS file input stream
System::SharedPtr<System::IO::FileStream> psStream = System::MakeObject<System::IO::FileStream>(dataDir + u"get_input.eps", System::IO::FileMode::Open, System::IO::FileAccess::Read);
// Create PsDocument instance from stream
System::SharedPtr<PsDocument> document = System::MakeObject<PsDocument>(psStream);


{
    auto __finally_guard_0 = ::System::MakeScopeGuard([&psStream]()
    {
        psStream->Close();
    });
    
    try
    {
        // Get XMP metadata. If EPS file doesn't contain XMP metadata we get new one filled with values from PS metadata comments (%%Creator, %%CreateDate, %%Title etc)
        System::SharedPtr<XmpMetadata> xmp = document->GetXmpMetadata();
        
        // Get "CreatorTool" value
        if (xmp->Contains(u"xmp:CreatorTool"))
        {
            System::Console::WriteLine(System::String(u"CreatorTool: ") + xmp->idx_get(u"xmp:CreatorTool")->ToStringValue());
        }
        
        // Get "CreateDate" value
        if (xmp->Contains(u"xmp:CreateDate"))
        {
            System::Console::WriteLine(System::String(u"CreateDate: ") + xmp->idx_get(u"xmp:CreateDate")->ToStringValue());
        }
        
        // Get a width of a thumbnail image if exists
        if (xmp->Contains(u"xmp:Thumbnails") && xmp->idx_get(u"xmp:Thumbnails")->get_IsArray())
        {
            System::SharedPtr<XmpValue> val = xmp->idx_get(u"xmp:Thumbnails")->ToArray()->idx_get(0);
            if (val->get_IsNamedValues() && val->ToDictionary()->ContainsKey(u"xmpGImg:width"))
            {
                System::Console::WriteLine(System::String(u"Thumbnail Width: ") + val->ToDictionary()->idx_get(u"xmpGImg:width")->ToInteger());
            }
        }
        
        // Get "format" value
        if (xmp->Contains(u"dc:format"))
        {
            System::Console::WriteLine(System::String(u"Format: ") + xmp->idx_get(u"dc:format")->ToStringValue());
        }
        
        // Get "DocumentID" value
        if (xmp->Contains(u"xmpMM:DocumentID"))
        {
            System::Console::WriteLine(System::String(u"DocumentID: ") + xmp->idx_get(u"xmpMM:DocumentID")->ToStringValue());
        }
        
    }
    catch (...)
    {
        throw;
    }
}

请参阅在 Java 和 .NET 中提取 XMP 元数据。

您可以从 GitHub下载示例和数据文件。