通过 .NET SDK 从 PDF 获取页面注释

    using Aspose.Pdf.Cloud.Sdk.Model;

    namespace Annotations
    {
        public class GetAnnotations
        {
            public static async Task<string> RequestAnnotationsOnPageAsync(AnnotationsHelper helper, string documentName, int pageNumber, string remoteFolder)
            {
                // Get annotations from the page in the PDF document.
                await helper.UploadFile(documentName);

                string annotationResult = string.Empty;
                AnnotationsInfoResponse response = await helper.pdfApi.GetPageAnnotationsAsync(documentName, pageNumber, folder: remoteFolder);

                if (response == null)
                    Console.WriteLine("RequestAnnotationsOnPageAsync(): Unexpected error!");
                else if (response.Code < 200 || response.Code > 299)
                    Console.WriteLine("RequestAnnotationsOnPageAsync(): Failed to request annotations from the document.");
                else
                {
                    foreach (AnnotationInfo annotation in response.Annotations.List)
                    {
                        Console.WriteLine("RequestAnnotationsOnPageAsync(): annotation '{0}' with '{1}' contents get from the '{2}' page of the document '{3}.", [annotation.Id, annotation.Contents, pageNumber, documentName]);
                        if (string.IsNullOrEmpty(annotationResult) &&
                            annotation.AnnotationType == AnnotationType.Text)
                        {
                            annotationResult = annotation.Id;
                        }
                    }
                }
                return annotationResult;
            }
        }
}