pdfcompresser.cs

来自「PDF文件格式解析库源代码」· CS 代码 · 共 90 行

using System;
using System.Collections.Generic;
using System.Text;

namespace AnotherPDFLib
{
    public class PdfCompresser
    {
        public static void Compress(PdfDocument pdfdoc)
        {
            foreach (PdfObject pdfobj in pdfdoc.PdfObjects.Values)
            {
                CompressObject(pdfobj);
            }
        }

        public static void CompressObject(PdfObject pdfobj)
        {
            if (pdfobj is PdfDictionary)
            {
                PdfDictionary dict = pdfobj as PdfDictionary;
                foreach (PdfObject subpdfobj in dict.Entries.Values)
                {
                    if (!subpdfobj.IsIndirect)
                    {
                        CompressObject(subpdfobj);
                    }
                }

                if (pdfobj is PdfStream)
                {
                    PdfStream stream = pdfobj as PdfStream;
                    stream.EncodeStream();
                }
            }
            else if (pdfobj is PdfArray)
            {
                PdfArray array = pdfobj as PdfArray;
                foreach (PdfObject subpdfobj in array.Items)
                {
                    if (!subpdfobj.IsIndirect)
                    {
                        CompressObject(subpdfobj);
                    }
                }
            }
        }

        public static void DeCompress(PdfDocument pdfdoc)
        {
            foreach (PdfObject pdfobj in pdfdoc.PdfObjects.Values)
            {
                DeCompressObject(pdfobj);
            }
        }

        public static void DeCompressObject(PdfObject pdfobj)
        {
            if (pdfobj is PdfDictionary)
            {
                PdfDictionary dict = pdfobj as PdfDictionary;
                foreach (PdfObject subpdfobj in dict.Entries.Values)
                {
                    if (!subpdfobj.IsIndirect)
                    {
                        DeCompressObject(subpdfobj);
                    }
                }

                if (pdfobj is PdfStream)
                {
                    PdfStream stream = pdfobj as PdfStream;
                    stream.DecodeStream();
                }
            }
            else if (pdfobj is PdfArray)
            {
                PdfArray array = pdfobj as PdfArray;
                foreach (PdfObject subpdfobj in array.Items)
                {
                    if (!subpdfobj.IsIndirect)
                    {
                        DeCompressObject(subpdfobj);
                    }
                }
            }
        }
    }
}