PDF转图片（O2S.Components.PDFRender4NET ）

1.PDF生成IMG的帮助类

using O2S.Components.PDFRender4NET;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MysteelData.Common
{
   public static class PDFHelper
    {
     
           public enum Definition
           {
               One = 1, Two = 2, Three = 3, Four = 4, Five = 5, Six = 6, Seven = 7, Eight = 8, Nine = 9, Ten = 10
           }
           /// <summary>
           /// 将PDF文档转换为图片的方法
           /// </summary>
           /// <param name="pdfInputPath">PDF文件路径</param>
           /// <param name="imageOutputPath">图片输出路径</param>
           /// <param name="imageName">生成图片的名字</param>
           /// <param name="startPageNum">从PDF文档的第几页开始转换</param>
           /// <param name="endPageNum">从PDF文档的第几页开始停止转换</param>
           /// <param name="imageFormat">设置所需图片格式</param>
           /// <param name="definition">设置图片的清晰度，数字越大越清晰</param>
           public static void ConvertPDF2Image(Stream pdfInputPath, string imageOutputPath,
               string imageName, int startPageNum, int endPageNum, ImageFormat imageFormat, Definition definition)
           {
               PDFFile pdfFile = PDFFile.Open(pdfInputPath);

               if (!Directory.Exists(imageOutputPath))
               {
                   Directory.CreateDirectory(imageOutputPath);
               }

               // validate pageNum
               if (startPageNum <= 0)
               {
                   startPageNum = 1;
               }

               if (endPageNum > pdfFile.PageCount)
               {
                   endPageNum = pdfFile.PageCount;
               }

               if (startPageNum > endPageNum)
               {
                   int tempPageNum = startPageNum;
                   startPageNum = endPageNum;
                   endPageNum = startPageNum;
               }

               // start to convert each page
               for (int i = startPageNum; i <= endPageNum; i++)
               {
                   Bitmap pageImage = pdfFile.GetPageImage(i - 1, 56 * (int)definition);
                   pageImage.Save(imageOutputPath + imageName + i.ToString() + "." + imageFormat.ToString(), imageFormat);
                   pageImage.Dispose();
               }

               pdfFile.Dispose();
           }
       
    }
}

2.MVC中使用

      public ActionResult Details(long Id, string Title)
        {
            byte[] fileByte = null;
            try
            {
                 //压缩文件流
                fileByte = CompressionUtilHelper.Decompress(MacroSpeBLL.GetMaHotAnalysisAttachPathById(Id));
                Stream stream = new MemoryStream(fileByte);
                PDFFile pdfFile = PDFFile.Open(stream);
                int number = pdfFile.PageCount;
                string imglist = string.Empty;
                string imageName = Id + "_mysteel" + "_";
                for (int j = 1; j <= number; j++)
                {
                    string imgExtensionName = imageName + j + ".Jpeg";
                    if (!new FileInfo(Server.MapPath("~/PdfImages/" + imgExtensionName)).Exists)
                    {
                        PDFHelper.ConvertPDF2Image(stream, files, imageName, j, j, ImageFormat.Jpeg, PDFHelper.Definition.Three);
                    }
                    imglist += imgExtensionName + ",";
                }
                return Content(imglist.Substring(0, imglist.Length - 1));
            }
            catch (Exception)
            {
                return Content(string.Empty);
            }

        }

3.涉及到的文件流压缩类

using System.IO;
using System.IO.Compression;
using System.Linq;

namespace MySteel.Common.Helper
{
    /// <summary>
    /// 压缩处理数据帮助类
    /// </summary>
    public class CompressionUtilHelper
    {
        /// <summary>
        /// 压缩数据
        /// </summary>
        /// <param name="source"></param>
        /// <param name="dest"></param>
        public static void Compress(Stream source, Stream dest)
        {
            using (GZipStream zipStream = new GZipStream(dest, CompressionMode.Compress, true))
            {
                byte[] buf = new byte[1024];
                int len;
                while ((len = source.Read(buf, 0, buf.Length)) > 0)
                {
                    zipStream.Write(buf, 0, len);
                }
            }
        }

        /// <summary>
        /// 解压数据
        /// </summary>
        /// <param name="source"></param>
        /// <param name="dest"></param>
        public static void Decompress(Stream source, Stream dest)
        {
            using (GZipStream zipStream = new GZipStream(source, CompressionMode.Decompress, true))
            {
                byte[] buf = new byte[1024];
                int len;
                while ((len = zipStream.Read(buf, 0, buf.Length)) > 0)
                {
                    dest.Write(buf, 0, len);
                }
            }
        }

        /// <summary>
        /// 压缩数据
        /// </summary>
        /// <param name="Source"></param>
        public static byte[] Compress(byte[] Source)
        {
            MemoryStream stream = new MemoryStream();
            GZipStream gZipStream = new GZipStream(stream, CompressionMode.Compress);

            gZipStream.Write(Source, 0, Source.Length);
            gZipStream.Close();

            return stream.ToArray();
        }

        ///// <summary>
        ///// 解压数据
        ///// </summary>
        ///// <param name="Source"></param>
        public static byte[] Decompress(byte[] Source)
        {
            MemoryStream stream = new MemoryStream();
            GZipStream gZipStream = new GZipStream(new MemoryStream(Source), CompressionMode.Decompress);

            byte[] b = new byte[4096];
            int count = 0;
            while (true)
            {
                int n = gZipStream.Read(b, 0, b.Length);

                if (n > 0)
                {
                    stream.Write(b, 0, n);
                    count += n;
                }
                else
                {
                    gZipStream.Close();
                    break;
                }
            }

            return stream.ToArray().Take(count).ToArray();
        }
    }
}