Question

任何人都知道如何使用C#中的itextsharp库识别pdf方向，无论是横向还是纵向。

以下是我的代码，它正在检索PDF流并旋转图像，但我的问题是我们如何识别方向？

public static string ReadPdfFile(string fileName)
        {
        StringBuilder text = new StringBuilder();

        if (File.Exists(fileName))
        {




            byte[] bytes = System.IO.File.ReadAllBytes(fileName);



            using (MemoryStream ms = new MemoryStream())
            {
                Document doc = new Document();
                PdfWriter writer = PdfWriter.GetInstance(doc, ms);
                doc.Open();
                PdfContentByte cb = writer.DirectContent;
                PdfImportedPage page;
                PdfReader reader;
                reader = new PdfReader(bytes);
                int pages = reader.NumberOfPages;

                // loop over document pages
                for (int i = 1; i <= pages; i++)
                {

                    page = writer.GetImportedPage(reader, i);
                    //Rectangle pagesize = reader.GetPageSizeWithRotation(0);
                    AffineTransform scale = new AffineTransform(0, 1.0F, -1.0F, 0, 500, 500);
                    cb.AddTemplate(page,scale);
                }

                doc.Close();
                var rotatedFile =  ms.GetBuffer();

                ms.Flush();
                ms.Dispose();
                string filepath = @"D:\test2.pdf";
                File.Delete(filepath);
                using (FileStream Writer = new System.IO.FileStream(filepath, FileMode.Create, FileAccess.Write))
                {
                    Writer.Write(rotatedFile, 0, rotatedFile.Length);
                    string actualFilePath = "test2.pdf";
                    filepath = actualFilePath;
                }


            }

请帮助我，提前致谢！

Answer 1

我评估页面的矩形大小以找出它。要注意的事项......您可以在同一个文件中拥有多个方向，因此您无法仅根据第一页来确定文件是否为横向。如果所有页面都是横向的，则文件是横向的，否则它是混合的方向文件。

require(shiny)

datas <- data.frame(directory = c(puntaje_2016_1$estu_reside_depto), file = c(puntaje_2016_1$estu_reside_mcpio) , cole = c(puntaje_2016_1$cole_nombre_sede) )


runApp(list(
  ui = basicPage(
    sidebarPanel(
      selectInput("directory", "Select a directory", choices = levels(datas$directory), selected = levels(datas$directory)[1]),
      tags$hr(),
      selectInput("files", "Select files", choices = datas$file[datas$directory == levels(datas$directory)[1]], multiple = FALSE)
     ## tags$hr()
      ##selectInput("cole", "Select files", choices = datas$cole[datas$file == levels(datas$file)[1]], multiple = FALSE)
          )
  ),
  server = function(input, output, session) {

observe({
  directory <- input$directory
  updateSelectInput(session, "files", choices = datas$file[datas$directory == directory])
      })
##observe({
  ##files<-input$files 
  ##updateSelectInput(session, "coles", choice = datas$cole[datas$file == ##files])
   ## })
  }
))

如何在C＃中使用itextsharp库识别pdf方向，无论是横向还是纵向

1 个答案: