删除注释（外观）

从现有 PDF 文件中删除所有注释

PdfAnnotationEditor 允许您从现有 PDF 文件中删除所有注释。首先，创建一个 PdfAnnotationEditor 对象，并使用 BindPdf 方法绑定输入 PDF 文件。之后，调用 DeleteAnnotations 方法以删除文件中的所有注释，然后使用 Save 方法保存更新后的 PDF 文件。以下代码片段演示了如何从 PDF 文件中删除所有注释。

.NET Core 3.1

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.Pdf-for-.NET
private static void DeleteAllAnnotations()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Annotations();

    // Create an instance of PdfAnnotationEditor
    using (var annotationEditor = new Aspose.Pdf.Facades.PdfAnnotationEditor())
    {
        // Bind PDF document
        annotationEditor.BindPdf(dataDir + "DeleteAllAnnotationsFromPage.pdf");

        // Delete all annoations
        annotationEditor.DeleteAnnotations();

        // Save PDF document
        annotationEditor.Save(dataDir + "DeleteAllAnnotationsFromPage_out.pdf");
    }
}

.NET 8

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.Pdf-for-.NET
private static void DeleteAllAnnotations()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Annotations();

    // Create an instance of PdfAnnotationEditor
    using var annotationEditor = new Aspose.Pdf.Facades.PdfAnnotationEditor();

    // Bind PDF document
    annotationEditor.BindPdf(dataDir + "DeleteAllAnnotationsFromPage.pdf");

    // Delete all annoations
    annotationEditor.DeleteAnnotations();

    // Save PDF document
    annotationEditor.Save(dataDir + "DeleteAllAnnotationsFromPage_out.pdf");
}

按指定类型删除所有注释

您可以使用 PdfAnnotationEditor 类按指定注释类型从现有 PDF 文件中删除所有注释。为此，您需要创建一个 PdfAnnotationEditor 对象，并使用 BindPdf 方法绑定输入 PDF 文件。之后，调用 DeleteAnnotations 方法，并传入字符串参数，以删除文件中的所有注释；字符串参数表示要删除的注释类型。最后，使用 Save 方法保存更新后的 PDF 文件。以下代码片段演示了如何按指定注释类型删除所有注释。

.NET Core 3.1

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.Pdf-for-.NET
private static void DeleteAllAnnotationByType()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdfFacades_Annotations();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "DeleteAllAnnotations.pdf"))
    {
        // Collect all annotation types from all pages
        var annotationTypes = new List<string>();
        foreach (Aspose.Pdf.Page page in document.Pages)
        {
            // If page has no annotations, skip it
            if (page.Annotations == null)
            {
                continue;
            }

            // Retrieve each annotation type from the page
            IEnumerable<string> pageAnnotationTypes = page.Annotations.Select(ann => ann.AnnotationType.ToString());
            annotationTypes.AddRange(pageAnnotationTypes);
        }

        // Make the list of annotation types distinct
        annotationTypes = annotationTypes.Distinct().ToList();

        // Display each annotation type to the user
        int index;
        for (index = 0; index < annotationTypes.Count; index++)
        {
            Console.WriteLine($"{index + 1}. {annotationTypes[index]}");
        }

        // Prompt user to choose the annotation type to delete
        Console.Write("Please enter number: ");
        index = int.Parse(Console.ReadLine()) - 1;

        // Create an instance of PdfAnnotationEditor
        using (var annotationEditor = new Aspose.Pdf.Facades.PdfAnnotationEditor())
        {
            // Bind PDF document
            annotationEditor.BindPdf(document);

            // Delete the annotation selected by the user
            annotationEditor.DeleteAnnotations(annotationTypes[index]);

            // Save PDF document
            annotationEditor.Save(dataDir + "DeleteAllAnnotationByType_out.pdf");
        }
    }
}

.NET 8

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.Pdf-for-.NET
private static void DeleteAllAnnotationByType()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdfFacades_Annotations();

    // Open PDF document
    using var document = new Aspose.Pdf.Document(dataDir + "DeleteAllAnnotations.pdf");

    // Collect all annotation types from all pages
    var annotationTypes = new List<string>();
    foreach (Aspose.Pdf.Page page in document.Pages)
    {
        // If page has no annotations, skip it
        if (page.Annotations == null)
        {
            continue;
        }

        // Retrieve each annotation type from the page
        IEnumerable<string> pageAnnotationTypes = page.Annotations.Select(ann => ann.AnnotationType.ToString());
        annotationTypes.AddRange(pageAnnotationTypes);
    }

    // Make the list of annotation types distinct
    annotationTypes = annotationTypes.Distinct().ToList();

    // Display each annotation type to the user
    int index;
    for (index = 0; index < annotationTypes.Count; index++)
    {
        Console.WriteLine($"{index + 1}. {annotationTypes[index]}");
    }

    // Prompt user to choose the annotation type to delete
    Console.Write("Please enter number: ");
    index = int.Parse(Console.ReadLine()) - 1;

    // Create an instance of PdfAnnotationEditor
    using var annotationEditor = new Aspose.Pdf.Facades.PdfAnnotationEditor();

    // Bind PDF document
    annotationEditor.BindPdf(document);

    // Delete the annotation selected by the user
    annotationEditor.DeleteAnnotations(annotationTypes[index]);

    // Save PDF document
    annotationEditor.Save(dataDir + "DeleteAllAnnotationByType_out.pdf");
}

按指定名称删除注释

您可以使用 PdfAnnotationEditor 类按其 唯一名称 删除现有 PDF 文件中的特定注释。为此，您需要创建一个 PdfAnnotationEditor 对象，并使用 BindPdf 方法绑定输入 PDF 文件。之后，调用 DeleteAnnotation 方法，传入要删除的注释名称。最后，使用 Save 方法存储更新后的 PDF 文件。以下代码片段演示了如何按名称删除注释。

.NET Core 3.1

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.Pdf-for-.NET
private static void DeleteAnnotationByName()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdfFacades_Annotations();

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "DeleteAllAnnotations.pdf"))
    {
        // Display the list of annotations in the first page (adjust as needed for multiple pages)
        int index;
        for (index = 1; index <= document.Pages[1].Annotations.Count; index++)
        {
            Console.WriteLine($"{index}. {document.Pages[1].Annotations[index].Name} {document.Pages[1].Annotations[index].AnnotationType}");
        }

        // Prompt the user to enter the index of the annotation to delete
        Console.Write("Please enter number: ");
        index = int.Parse(Console.ReadLine());

        // Create an instance of PdfAnnotationEditor
        using (var annotationEditor = new Aspose.Pdf.Facades.PdfAnnotationEditor())
        {
            // Bind PDF document
            annotationEditor.BindPdf(document);

            // Delete the annotation selected by the user
            annotationEditor.DeleteAnnotation(document.Pages[1].Annotations[index].Name);

            // Save PDF document
            annotationEditor.Save(dataDir + "DeleteAnnotationByName_out.pdf");
        }
    }
}

.NET 8

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.Pdf-for-.NET
private static void DeleteAnnotationByName()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdfFacades_Annotations();

    // Open PDF document
    using var document = new Aspose.Pdf.Document(dataDir + "DeleteAllAnnotations.pdf");

    // Display the list of annotations in the first page (adjust as needed for multiple pages)
    int index;
    for (index = 1; index <= document.Pages[1].Annotations.Count; index++)
    {
        Console.WriteLine($"{index}. {document.Pages[1].Annotations[index].Name} {document.Pages[1].Annotations[index].AnnotationType}");
    }

    // Prompt the user to enter the index of the annotation to delete
    Console.Write("Please enter number: ");
    index = int.Parse(Console.ReadLine());

    // Create an instance of PdfAnnotationEditor
    using var annotationEditor = new Aspose.Pdf.Facades.PdfAnnotationEditor();

    // Bind PDF document
    annotationEditor.BindPdf(document);

    // Delete the annotation selected by the user
    annotationEditor.DeleteAnnotation(document.Pages[1].Annotations[index].Name);

    // Save PDF document
    annotationEditor.Save(dataDir + "DeleteAnnotationByName_out.pdf");
}