今天由于工作需要，研究了将PDF文件转换为图片的一些小方法。翻破网络都没有找到相关资料，一个偶然，庆幸自己找到准确信息（http://www.codeproject.com/KB/GDI-plus/pdfthumbnail.aspx），特将一些信息贴出来，供大家参考！

需要引用两个连接库，1、Com组件Acrobat（Adobe Acrobat Professional）；2、.Net组件Microdoft.VisualBasic。

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Windows.Forms;
using System.Drawing;
using System.Runtime.InteropServices;

namespace AdaEniac
{
    public class ConvertPdfToPicture
    {
        private Acrobat.CAcroPDDoc pdfDoc;
        private Acrobat.CAcroPDPage pdfPage;
        private Acrobat.CAcroRect pdfRect;
        private Acrobat.CAcroPoint pdfPoint;

        public ConvertPdfToPicture()
        {
        }

        public void ConvertToPicture(string[] pcFileNames)
        {
            try
            {
                //Pdf 文件数量判断
                for (int n = 0; n < 1; n++)
                {
                    string lcFileName = pcFileNames[n].ToString();
                    string lcOutPutFile = lcFileName.Replace(“.pdf”, “”);

                    pdfDoc = (Acrobat.CAcroPDDoc)Microsoft.VisualBasic.Interaction.CreateObject(“AcroExch.PDDoc”, “”);
                    bool llRet = pdfDoc.Open(lcFileName);

                    if (!llRet)
                    {
                        throw new FileNotFoundException();
                    }

                    int pageCount = pdfDoc.GetNumPages();
                    for (int i = 0; i < pageCount; i++)
                    {
                        pdfPage = (Acrobat.CAcroPDPage)pdfDoc.AcquirePage(i);
                        pdfPoint = (Acrobat.CAcroPoint)pdfPage.GetSize();
                        pdfRect = (Acrobat.CAcroRect)Microsoft.VisualBasic.Interaction.CreateObject(“AcroExch.Rect”, “”);
                        pdfRect.Left = 0;
                        pdfRect.right = pdfPoint.x;
                        pdfRect.Top = 0;
                        pdfRect.bottom = pdfPoint.y;

                        pdfPage.CopyToClipboard(pdfRect, 0, 0, 100);

                        IDataObject loClipboardData = Clipboard.GetDataObject();
                        if (loClipboardData.GetDataPresent(DataFormats.Bitmap))
                        {
                            Bitmap pdfBitmap = (Bitmap)loClipboardData.GetData(DataFormats.Bitmap);
                            int loImgWidth = pdfPoint.x;
                            int loImgHeight = pdfPoint.y;

                            if (pdfPoint.x >= pdfPoint.y)
                            {
                                loImgWidth = loImgWidth ^ loImgHeight;
                                loImgHeight = loImgWidth ^ loImgHeight;
                                loImgWidth = loImgWidth ^ loImgHeight;
                            }

                            Bitmap loTemplateBitmap = new Bitmap(pdfPoint.x, pdfPoint.y);

                            Image loPdfImage = pdfBitmap.GetThumbnailImage(loImgWidth, loImgHeight, null, IntPtr.Zero);

                            Bitmap thumbnailBitmap = new Bitmap(loImgWidth + 7, loImgHeight + 7, System.Drawing.Imaging.PixelFormat.Format32bppArgb);

                            // http://www.sellsbrothers.com/writing/default.aspx?content=dotnetimagerecoloring.htm
                            loTemplateBitmap.MakeTransparent();

                            using (Graphics poGraphics = Graphics.FromImage(thumbnailBitmap))
                            {
                                poGraphics.DrawImage(loPdfImage, 2, 2, loImgWidth, loImgHeight);
                                poGraphics.DrawImage(loTemplateBitmap, 0, 0);
                                //保存图象文件
                                string lcSaveFileName = lcOutPutFile + i.ToString() + “.png”;
                                thumbnailBitmap.Save(lcSaveFileName, System.Drawing.Imaging.ImageFormat.Png);
                            }

                            loTemplateBitmap.Dispose();
                            loPdfImage.Dispose();
                            thumbnailBitmap.Dispose();
                        }
                    }
                    pdfDoc.Close();

                    // see http://blogs.msdn.com/yvesdolc/archive/2004/04/17/115379.aspx
                    Marshal.ReleaseComObject(pdfPage);
                    Marshal.ReleaseComObject(pdfRect);
                    Marshal.ReleaseComObject(pdfDoc);
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
    }
}