为图像设置替代文本

以下代码片段也适用于 Aspose.PDF.Drawing 库。

XImage 类包含 GetAlternativeText 和 TrySetAlternativeText 方法，允许您获取和设置与图像对应的替代文本。

以下代码片段向您展示如何使用这些方法在 PDF 文件中设置图像的替代文本并获取它。

.NET Core 3.1

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

    // Open PDF document
    using (var document = new Aspose.Pdf.Document(dataDir + "SearchAndGetImages.pdf"))
    {
        // Alternative text to be given to the image 
        string altText = "Alternative text for image";

        // Image for which alternative text will be set and get
        XImage xImage = document.Pages[1].Resources.Images[1];

        // Try to set alternative text for an image
        bool result = xImage.TrySetAlternativeText(altText, document.Pages[1]);

        // If set is successful, then get the alternative text for the image
        if (result)
        {
            List<string> altTexts = xImage.GetAlternativeText(document.Pages[1]);
        }

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

.NET 8

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

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

    // Alternative text to be given to the image 
    string altText = "Alternative text for image";

    // Image for which alternative text will be set and get
    XImage xImage = document.Pages[1].Resources.Images[1];

    // Try to set alternative text for an image
    bool result = xImage.TrySetAlternativeText(altText, document.Pages[1]);

    // If set is successful, then get the alternative text for the image
    if (result)
    {
        List<string> altTexts = xImage.GetAlternativeText(document.Pages[1]);
    }

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