using System.Collections.Generic;using System.IO;using iTextSharp.text;using iTextSharp.text.pdf;namespace Pdf{    /// <summary>    /// Pdf文件信息    /// 印刷文件最多两页，且每页的长宽一样的    /// </summary>    public class PdfFileInfo    {        public string path { get; set; }        public float width { get; set; }        public float height { get; set; }        public float X { get; set; }        public float Y { get; set; }    }    /// <summary>    /// pdf操作核心类    /// </summary>    public class PdfMange    {        /// <summary>        /// 读取多个pdf文件，按照每个pdf文件顺序+页面顺序合并到一个pdf文件中        /// </summary>        /// <param name="fileList"></param>        /// <param name="targetFile"></param>        public static void ComBineMoreToOne(string[] fileList, string targetFile)        {            PdfReader reader;            Document document = new Document();            PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(targetFile, FileMode.Create));            document.Open();            PdfContentByte cb = writer.DirectContent;            PdfImportedPage newPage;            for (int i = 0; i < fileList.Length; i++)            {                reader = new PdfReader(fileList[i]);                int iPageNum = reader.NumberOfPages;                for (int j = 1; j <= iPageNum; j++)                {                    newPage = writer.GetImportedPage(reader, j);                    document.NewPage();                    cb.AddTemplate(newPage, 0, 0);                }            }            document.Close();        }        /// <summary>        /// 读取多个pdf文件，按照每个pdf文件顺序+页面顺序合并到一个pdf文件中的一页上，并且自动适应大小排序        /// 1英寸=72磅     2.54厘米=1英寸   pdf单位磅        /// </summary>        /// <param name="fileList"></param>        /// <param name="targetFile"></param>        public static void ComBineMoreToOnePage(IList<PdfFileInfo> fileList, string targetFile)        {            float[] urx2 = GetUrxy(fileList);            float urx = urx2[0], ury = urx2[1];            int marginLeft = 0, marginRight = 0, marginTop = 0, marginBottom = 0;            iTextSharp.text.Rectangle pagesize = new iTextSharp.text.Rectangle(urx, ury);            Document document = new Document(pagesize, marginLeft, marginRight, marginTop, marginBottom);            PdfReader reader;            PdfImportedPage newPage;            PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(targetFile, FileMode.Create));            document.Open();            PdfContentByte cb = writer.DirectContent;            //=================================关键复制pdf内容代码段Start===============================================            foreach (PdfFileInfo info in fileList)            {                reader = new PdfReader(info.path);                int PageNum = reader.NumberOfPages;                for (int j = 1; j <= PageNum; j++)                {                    if (j % 2 != 0&&j<3)//印刷行业规定最多只有2页，且只有一页的第二页要空                    {                        newPage = writer.GetImportedPage(reader, j);                        cb.AddTemplate(newPage, info.X, info.Y);                    }                }            }            document.NewPage();            foreach (PdfFileInfo info in fileList)            {                reader = new PdfReader(info.path);                int PageNum = reader.NumberOfPages;                for (int j = 1; j <= PageNum; j++)                {                    if (j % 2 == 0 && j < 3)//印刷行业规定最多只有2页，且只有一页的第二页要空                    {                        newPage = writer.GetImportedPage(reader, j);                        cb.AddTemplate(newPage, info.X, info.Y);                    }                }            }            //=================================关键复制pdf内容代码段end===============================================            document.Close();        }        public static float[] GetUrxy(IList<PdfFileInfo> fileList)        {            IList<float> x = new List<float>();            IList<float> y = new List<float>();            foreach (PdfFileInfo info in fileList)            {                x.Add(info.width + info.X);                y.Add(info.height + info.Y);            }            for (int i = 0; i < x.Count; i++)            {                float temp = x[i];                for (int j = 0; j < x.Count; j++)                {                    if (x[j] < x[i])                    {                        x[i] = x[j];                        x[j] = temp;                    }                }            }            for (int i = 0; i < y.Count; i++)            {                float temp = y[i];                for (int j = 0; j < y.Count; j++)                {                    if (y[j] < y[i])                    {                        y[i] = y[j];                        y[j] = temp;                    }                }            }            float[] result = { x[0], y[0] };            return result;        }        /// <summary>        /// 计算pdf 毫米转磅        /// </summary>        /// <param name="size"></param>        /// <returns></returns>        public static float GetPdfSize(float size)        {            return (size / 10) / (float)2.54*(float)72;        }        //==============================================================================================================================================    }}

/// <summary>        /// 合并多个pdf文件        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private void button4_Click(object sender, EventArgs e)        {            List<PdfFileInfo> fileList = new List<PdfFileInfo>();            PdfFileInfo info = new PdfFileInfo();            info.path = "c://41.pdf";            info.X = 0;            info.Y = 0;            info.width = PdfMange.GetPdfSize(210);            info.height = PdfMange.GetPdfSize(297);            fileList.Add(info);            PdfFileInfo info2 = new PdfFileInfo();            info2.path = "c://5.pdf";            info2.X = PdfMange.GetPdfSize(210);             info2.Y = 0;            info2.width = PdfMange.GetPdfSize(210);            info2.height = PdfMange.GetPdfSize(297);            fileList.Add(info2);            PdfFileInfo info3 = new PdfFileInfo();            info3.path = "c://442.pdf";            info3.X = PdfMange.GetPdfSize(210*2); ;            info3.Y = 0;            info3.width = PdfMange.GetPdfSize(210);            info3.height = PdfMange.GetPdfSize(297);            fileList.Add(info3);            PdfMange.ComBineMoreToOnePage(fileList, "c://newpdf.pdf");        }