Bagaimana untuk Menghapuskan Ruang Putih Menegak Apabila Menggabungkan Fail PDF dalam C#?

Cara Mengalih Keluar Ruang Putih pada Gabungan

Kod ini menggabungkan tiga tatasusunan bait PDF dengan cekap. Walau bagaimanapun, dokumen yang terhasil mempamerkan ruang putih menegak pada setiap halaman, menjadikannya kelihatan sebagai halaman berasingan. Begini cara untuk menghapuskan ruang kosong ini:

Pelaksanaan C# (Dikemas kini)

public class PdfVeryDenseMergeTool
{
    private Rectangle PageSize;
    private float TopMargin;
    private float BottomMargin;
    private float Gap;
    private Document Document = null;
    private PdfWriter Writer = null;
    private float YPosition = 0;

    public PdfVeryDenseMergeTool(Rectangle size, float top, float bottom, float gap)
    {
        this.PageSize = size;
        this.TopMargin = top;
        this.BottomMargin = bottom;
        this.Gap = gap;
    } // PdfVeryDenseMergeTool

    public void Merge(MemoryStream outputStream, List<PdfReader> inputs)
    {
        try
        {
            this.OpenDocument(outputStream);

            foreach (PdfReader reader in inputs)
            {
                this.Merge(reader);
            } // foreach of the PDF files to merge
        }
        finally
        {
            this.CloseDocument();
        } // try-catch-finally
    } // Merge

    public void OpenDocument(MemoryStream outputStream)
    {
        this.Document = new Document(PageSize, 36, 36, this.TopMargin, this.BottomMargin);
        this.Writer = PdfWriter.GetInstance(Document, outputStream);

        this.Document.Open();
        this.NewPage();
    } // OpenDocument

    public void CloseDocument()
    {
        try
        {
            this.Document.Close();
        }
        finally
        {
            this.Document = null;
            this.Writer = null;
            this.YPosition = 0;
        } // try-finally
    } // CloseDocument

    public void NewPage()
    {
        this.Document.NewPage();
        this.YPosition = PageSize.GetTop(this.TopMargin);
    } // Merge

    public void Merge(PdfReader reader)
    {
        PdfReaderContentParser parser = new PdfReaderContentParser(reader);

        for (int pageIndex = 1; pageIndex <= reader.NumberOfPages; pageIndex++)
        {
            this.Merge(reader, parser, pageIndex);
        } // foreach of the pages of the current PDF
    } // Merge

    public void Merge(PdfReader reader, PdfReaderContentParser parser, int pageIndex)
    {
        PdfImportedPage importedPage = Writer.GetImportedPage(reader, pageIndex);
        PdfContentByte directContent = Writer.DirectContent;

        PageVerticalAnalyzer finder = parser.ProcessContent(pageIndex, new PageVerticalAnalyzer());

        if (finder.VerticalFlips.Count < 2)
            return;

        Rectangle pageSizeToImport = reader.GetPageSize(pageIndex);

        int startFlip = finder.VerticalFlips.Count - 1;
        bool first = true;

        while (startFlip > 0)
        {
            if (!first)
                this.NewPage();

            float freeSpace = this.YPosition - PageSize.GetBottom(BottomMargin);
            int endFlip = startFlip + 1;

            while ((endFlip > 1) &amp;&amp; (finder.VerticalFlips[startFlip] - finder.VerticalFlips[endFlip - 2] < freeSpace))
                endFlip -= 2;

            if (endFlip < startFlip)
            {
                float height = finder.VerticalFlips[startFlip] - finder.VerticalFlips[endFlip];

                directContent.SaveState();
                directContent.Rectangle(0, this.YPosition - height, pageSizeToImport.Width, height);
                directContent.Clip();
                directContent.NewPath();

                this.Writer.DirectContent.AddTemplate(importedPage, 0, this.YPosition - (finder.VerticalFlips[startFlip] - pageSizeToImport.Bottom));

                directContent.RestoreState();
                this.YPosition -= height + this.Gap;
                startFlip = endFlip - 1;
            }
            else if (!first)
            {
                throw new ArgumentException(string.Format("Page {0} content too large", pageIndex));
            } // if

            first = false;
        } // while
    } // Merge
} // PdfVeryDenseMergeTool

Kelas PageVerticalAnalyzer:

public class PageVerticalAnalyzer : IRenderListener
{
    public PageVerticalAnalyzer() { }

    public List<float> VerticalFlips = new List<float>();

    public void AddVerticalUseSection(float from, float to)
    {
        if (to < from)
        {
            float temp = to;
            to = from;
            from = temp;
        }

        int i = 0;
        int j = 0;

        for (i = 0; i < VerticalFlips.Count; i++)
        {
            float flip = VerticalFlips[i];
            if (flip < from)
                continue;

            for (j = i; j < VerticalFlips.Count; j++)
            {
                flip = VerticalFlips[j];
                if (flip < to)
                    continue;
                break;
            }
            break;
        } // foreach of the vertical flips

        bool fromOutsideInterval = i % 2 == 0;
        bool toOutsideInterval = j % 2 == 0;

        while (j-- > i)
            VerticalFlips.RemoveAt(j); // This was the problem line with just .Remove(j)
        if (toOutsideInterval)

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