PDFRender4NET的使用之pdf转图片

同样的需要第三方的.dll,http://www.o2sol.com/pdfview4net/download.htm

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 pdfConvert
{

    public class Program
    {
        public enum ImageMergeOrientation
        {
            Horizontal,
            Vertical
        }


        public static void Main(string[] args)
        { // pdf转图片
          //PDFTranImgHelp.ConvertPDF2Image(@"D:\Csharpstudy\pdfTojpg\test.pdf", @"D:\Csharpstudy\pdfTojpg\", "test",1, ImageFormat.Png, Definition.Five);
             //合并图片
          const string folderPath = @"D:\Csharpstudy\pdfTojpg";
          var images = new DirectoryInfo(folderPath).GetFiles("*.png", SearchOption.TopDirectoryOnly);

          CombineImages(images, @"D:\Csharpstudy\pdfTojpg\FinalImage_H.png");
          CombineImages(images, @"D:\Csharpstudy\pdfTojpg\FinalImage_V.png", ImageMergeOrientation.Vertical);  
        }
        public static void CombineImages(FileInfo[] files, string toPath, ImageMergeOrientation mergeType = ImageMergeOrientation.Vertical)
        {
            //change the location to store the final image.
            var finalImage = toPath;
            var imgs = files.Select(f => Image.FromFile(f.FullName));

            var finalWidth = mergeType == ImageMergeOrientation.Horizontal ?
                imgs.Sum(img => img.Width) :
                imgs.Max(img => img.Width);

            var finalHeight = mergeType == ImageMergeOrientation.Vertical ?
                imgs.Sum(img => img.Height) :
                imgs.Max(img => img.Height);

            var finalImg = new Bitmap(finalWidth, finalHeight);
            Graphics g = Graphics.FromImage(finalImg);
            g.Clear(SystemColors.AppWorkspace);

            var width = finalWidth;
            var height = finalHeight;
            var nIndex = 0;
            foreach (FileInfo file in files)
            {
                Image img = Image.FromFile(file.FullName);
                if (nIndex == 0)
                {
                    g.DrawImage(img, new Point(0, 0));
                    nIndex++;
                    width = img.Width;
                    height = img.Height;
                }
                else
                {
                    switch (mergeType)
                    {
                        case ImageMergeOrientation.Horizontal:
                            g.DrawImage(img, new Point(width, 0));
                            width += img.Width;
                            break;
                        case ImageMergeOrientation.Vertical:
                            g.DrawImage(img, new Point(0, height));
                            height += img.Height;
                            break;
                        default:
                            throw new ArgumentOutOfRangeException("mergeType");
                    }
                }
                img.Dispose();
            }
            g.Dispose();
            finalImg.Save(finalImage,ImageFormat.Png);
            finalImg.Dispose();
        }
    }
    public enum Definition
    {
        One = 1, Two = 2, Three = 3, Four = 4, Five = 5, Six = 6, Seven = 7, Eight = 8, Nine = 9, Ten = 10
    }

    public class PDFTranImgHelp
    {
        /// <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(string pdfInputPath, string imageOutputPath,
            string imageName, int startPageNum,  ImageFormat imageFormat, Definition definition)
        {
            PDFFile pdfFile = PDFFile.Open(pdfInputPath);
            if (!Directory.Exists(imageOutputPath))
            {
                Directory.CreateDirectory(imageOutputPath);
            }
            // validate pageNum
            if (startPageNum <= 0)
            {
                startPageNum = 1;
            }
           
             var 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();
        }

        #region 合并图片
        #endregion
    }
}