Change named value in XMP metadata of EPS|C++

In order to change named value in XMP metadata of EPS file it is necessary to do several steps:

1. Initialize an input stream for input EPS file.
2. Create an instance of PsDocument from created earlier input stream.
3. Get an instance of XmpMetadata from the PsDocument. If given EPS file doesn’t contain XMP metadata the new one will be created, filled in with values from PS metadata comments and returned to you.
4. Now you can change named value of structure metadata fields.
5. Initialize an output stream for output EPS file.
6. Save EPS file with changed XMP metadata.

Following code snippet shows how to change named value in XMP metadata in EPS file in C++:

// 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"add_named_value_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();
        
        //Change XMP metadata values
        
        // Add named value to "xmpTPg:MaxPageSize" structure.
        xmp->AddNamedValue(u"xmpTPg:MaxPageSize", u"stDim:newKey", System::MakeObject<XmpValue>(u"NewValue"));
        
        // Save EPS file with changed XMP metadata
        
        // Create ouput stream
        System::SharedPtr<System::IO::FileStream> outPsStream = System::MakeObject<System::IO::FileStream>(RunExamples::GetOutDir() + u"add_named_value_output.eps", System::IO::FileMode::Create, System::IO::FileAccess::Write);
        
        // Save EPS file
        
        {
            auto __finally_guard_1 = ::System::MakeScopeGuard([&outPsStream]()
            {
                outPsStream->Close();
            });
            
            try
            {
                document->Save(outPsStream);
                outPsStream->Flush();
            }
            catch (...)
            {
                throw;
            }
        }
        
    }
    catch (...)
    {
        throw;
    }
}

See changing named value in XMP metadata in Java and .NET.

You can download examples and data files from GitHub.