（三）拆分和合并PDF

来源：互联网发布：淘宝上怎么挣钱编辑：程序博客网时间：2024/04/30 05:20

1. 引用第三方itextsharp.dll文件

2. 前台页面设计

<html xmlns="http://www.w3.org/1999/xhtml"><head runat="server">    <title></title></head><body>    <form id="form1" runat="server">    <div>        上传：        <asp:FileUpload ID="FileUpload1" runat="server" />        <asp:Button ID="UploadBtn" runat="server" Text="Upload"             onclick="UploadBtn_Click" />        <br />        总页数：<asp:Label ID="TotalNumber" runat="server"></asp:Label><br />        起始页：<asp:TextBox ID="StartPage" runat="server"></asp:TextBox><br />        终止页：<asp:TextBox ID="EndPage" runat="server"></asp:TextBox><br />        拆分：        <asp:Button ID="Split" runat="server" Text="Split" OnClick="Split_Click" Width="96px" /><br />      </div>    </form></body></html>

3. 后台代码如下：

  public partial class SplitPDF : System.Web.UI.Page    {        protected void Page_Load(object sender, EventArgs e)        {        }        static string newFileName;        static string fileName = string.Empty;        static bool flag = false;        static PdfReader reader = null;        static int pdfNum = 0;        static string splitFileName = string.Empty;        // Upload the file        protected void Upload()        {            Random random = new Random();            int str = random.Next(4);            string strDate = DateTime.Now.ToString("yyyyMMddhhmmss") + str.ToString();            if (this.FileUpload1.HasFile)            {                int i = this.FileUpload1.FileName.LastIndexOf(".");                string extension = this.FileUpload1.FileName.Substring(i + 1);                if (extension.ToLower() == "pdf")                {                    fileName = this.FileUpload1.FileName;                    newFileName = strDate + fileName;                    string filePath = Server.MapPath("~/SplitBefore/") + newFileName;                    this.FileUpload1.SaveAs(filePath);                    reader = new PdfReader(filePath);                    pdfNum = reader.NumberOfPages;                    Label1.Text = pdfNum.ToString();                    flag = true;                    this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "success", "<script>alert('Upload Success')</script>");                }                else                {                    this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "type", "<script>alert('File Type Error')</script>");                }            }            else            {                this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "pdf", "<script>alert('Please choose a PDF file')</script>");            }        }        // Validate input number        protected bool ValidateInput()        {            Regex regex = new Regex(@"^\d+$");            if (regex.IsMatch(txtStartPage.Text) && regex.IsMatch(txtEndPage.Text))            {                if (int.Parse(txtEndPage.Text) < int.Parse(txtStartPage.Text))                {                    Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "inputNum", "<script>alert('End Page should more than start page!');</script>");                    return false;                }                else                {                    return true;                }            }            else            {                Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "error", "<script>alert('Input should be a mumber!');</script>");                return false;            }        }        // Split PDF        protected void Split()        {            if (flag == true)            {                if (ValidateInput())                {                    int startPage = 1;                    int endPage = pdfNum;                    startPage = int.Parse(txtStartPage.Text);                    endPage = int.Parse(txtEndPage.Text);                    if (startPage < 1 || endPage > pdfNum)                    {                        this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "pageError", "<script>alert('Input Page Error!')</script>");                    }                    else                    {                        Document document = new Document(reader.GetPageSizeWithRotation(startPage));                        string strNewDate = DateTime.Now.ToString("yyyyMMddhhmmss") + fileName;                        splitFileName = "split" + strNewDate;                        PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(Server.MapPath("~/SplitAfter/" + splitFileName), FileMode.Create));                        document.Open();                        PdfContentByte cb = writer.DirectContent;                        PdfImportedPage page;                        int rotation;                        while (startPage <= endPage)                        {                            document.SetPageSize(reader.GetPageSizeWithRotation(startPage));                            document.NewPage();                            page = writer.GetImportedPage(reader, startPage);                            rotation = reader.GetPageRotation(startPage);                            if (rotation == 90 || rotation == 270)                            {                                cb.AddTemplate(page, 0, -1f, 1f, 0, 0, reader.GetPageSizeWithRotation(startPage).Height);                            }                            else                            {                                cb.AddTemplate(page, 1f, 0, 0, 1f, 0, 0);                            }                            startPage++;                        }                        document.Close();                        lb.Text = splitFileName;                                   this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "ss", "<script>alert('Split Success')</script>");                        txtStartPage.Text = string.Empty;                        txtEndPage.Text = string.Empty;                        flag = false;                        reader = null;                    }                }            }            else            {                this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "upload", "<script>alert('Please upload pdf first')</script>");            }        }        protected void btnAdd_Click(object sender, EventArgs e)        {            Upload();        }        protected void btnSplit_Click(object sender, EventArgs e)        {            Split();        }        protected void lb_Click(object sender, EventArgs e)        {            Process.Start(Server.MapPath("~/SplitAfter/" + splitFileName));        }    }

4. 由于FileUpload只支持4MB文件，因此需要在Web.Config

    <httpRuntime maxRequestLength="400000" executionTimeout="3600"/>  </system.web>

合并PDF核心代码：

        protected void MergePDFFiles(string[] fileList, string outMergeFile)        {            PdfReader reader;            Document document = new Document();            // Define the output place, and add the document to the stream            PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(outMergeFile, FileMode.Create));            // Open document            document.Open();            // PDF ContentByte            PdfContentByte cb = writer.DirectContent;            // PDF import page            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++)                {                    document.NewPage();                    newPage = writer.GetImportedPage(reader, j);                    cb.AddTemplate(newPage, 0, 0);                }            }            document.Close();        }