无法使用Aspose.Pdf打印jpg

Question

我想加载一个JPEG文件，并在C# (.net Framework4.8)中用Aspose.Pdf打印它。我目前拥有的代码是：

public void PrintImage(string fileToPrint, string printerName, string jobName)
    {
      System.Drawing.Image srcImage = System.Drawing.Image.FromFile(fileToPrint);
      int h = srcImage.Height;
      int w = srcImage.Width;

      var doc = new Document();
      var page = doc.Pages.Add();
      var image = new Image();
      image.File = (fileToPrint);

      page.PageInfo.Height = (h);
      page.PageInfo.Width = (w);
      page.PageInfo.Margin.Bottom = (0);
      page.PageInfo.Margin.Top = (0);
      page.PageInfo.Margin.Right = (0);
      page.PageInfo.Margin.Left = (0);

      page.Paragraphs.Add(image);

      var viewer = new PdfViewer(doc);
      PrintUsingViewer(viewer, printerName, jobName);
    }

    private static void PrintUsingViewer(PdfViewer viewer, string printerName, string jobName)
    {
      viewer.AutoResize = true;         // Print the file with adjusted size
      viewer.AutoRotate = true;         // Print the file with adjusted rotation
      viewer.PrintPageDialog = false;   // Do not produce the page number dialog when printing

      var ps = new System.Drawing.Printing.PrinterSettings();
      var pgs = new System.Drawing.Printing.PageSettings();

      ps.PrinterName = printerName;
      viewer.PrinterJobName = jobName;

      viewer.PrintDocumentWithSettings(pgs, ps);
      viewer.Close();
    }

当我保存文档而不是打印并查看它时，它看起来很好(添加了图像)。但是，当尝试打印图像时，图像不会打印，页面仅为空白。

我想打印，而不是先将文档保存为PDF，然后再尝试打印已保存的PDF。有没有人看到我做错了什么？

Answer 1

解决方案是添加下面这行代码

doc.ProcessParagraphs();

紧跟在此行之后：

page.Paragraphs.Add(image);

所以代码现在变成了

public void PrintImage(string fileToPrint, string printerName, string jobName)
    {
      System.Drawing.Image srcImage = System.Drawing.Image.FromFile(fileToPrint);
      int h = srcImage.Height;
      int w = srcImage.Width;

      var doc = new Document();
      var page = doc.Pages.Add();
      var image = new Image();
      image.File = (fileToPrint);

      page.PageInfo.Height = (h);
      page.PageInfo.Width = (w);
      page.PageInfo.Margin.Bottom = (0);
      page.PageInfo.Margin.Top = (0);
      page.PageInfo.Margin.Right = (0);
      page.PageInfo.Margin.Left = (0);

      page.Paragraphs.Add(image);
      doc.ProcessParagraphs();

      var viewer = new PdfViewer(doc);
      PrintUsingViewer(viewer, printerName, jobName);
    }

    private static void PrintUsingViewer(PdfViewer viewer, string printerName, string jobName)
    {
      viewer.AutoResize = true;         // Print the file with adjusted size
      viewer.AutoRotate = true;         // Print the file with adjusted rotation
      viewer.PrintPageDialog = false;   // Do not produce the page number dialog when printing

      var ps = new System.Drawing.Printing.PrinterSettings();
      var pgs = new System.Drawing.Printing.PageSettings();

      ps.PrinterName = printerName;
      viewer.PrinterJobName = jobName;

      viewer.PrintDocumentWithSettings(pgs, ps);
      viewer.Close();
    }

现在图像打印正确了！