C#使用iTextSharp封装PDF操作类实现动态生成与排版

// 简单模式：A4纸，默认边距
var pdf = new PDFOperation();

// 高级模式：A4纸，左右边距36pt，上下边距72pt
var pdf = new PDFOperation("A4", 36f, 36f, 72f, 72f);

pdf.SetBaseFont(@"C:\Windows\Fonts\SIMHEI.TTF");
// 设置当前段落使用的字号，如12号字
pdf.SetFont(12f);

// 1. 打开文档
string path = "test.pdf";
using (FileStream fs = new FileStream(path, FileMode.Create))
{
    pdf.Open(fs);
    
    // 2. 添加带排版的标题
    // 参数：内容, 字号, 对齐(1居中), 段后空行, 段前空行, 行距倍数
    pdf.AddParagraph("测试文档（生成时间：" + DateTime.Now + "）", 15, 1, 20, 0, 0);
    
    // 3. 添加普通正文
    pdf.AddParagraph("这是正文内容...", 12);
    
    // 4. 关闭并保存
    pdf.Close();
}

using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace DotNet.Utilities
{
  public class PDFOperation
  {
    #region 构造函数
    public PDFOperation()
    {
      rect = PageSize.A4;
      document = new Document(rect);
    }

    public PDFOperation(string type)
    {
      SetPageSize(type);
      document = new Document(rect);
    }

    public PDFOperation(string type, float marginLeft, float marginRight, float marginTop, float marginBottom)
    {
      SetPageSize(type);
      document = new Document(rect, marginLeft, marginRight, marginTop, marginBottom);
    }
    #endregion

    #region 私有字段
    private Font font;
    private Rectangle rect;
    private Document document;
    private BaseFont basefont;
    #endregion

    #region 字体设置
    public void SetBaseFont(string path)
    {
      // IDENTITY_H 支持中文，NOT_EMBEDDED 减小文件体积
      basefont = BaseFont.CreateFont(path, BaseFont.IDENTITY_H, BaseFont.NOT_EMBEDDED);
    }

    public void SetFont(float size)
    {
      font = new Font(basefont, size);
    }
    #endregion

    #region 页面设置
    public void SetPageSize(string type)
    {
      switch (type.Trim())
      {
        case "A4":
          rect = PageSize.A4;
          break;
        case "A8":
          rect = PageSize.A8;
          break;
        default:
          rect = PageSize.A4; // 默认回退
          break;
      }
    }
    #endregion

    #region 文档生命周期
    public void GetInstance(Stream os)
    {
      PdfWriter.GetInstance(document, os);
    }

    public void Open(Stream os)
    {
      GetInstance(os);
      document.Open();
    }

    public void Close()
    {
      document.Close();
    }
    #endregion

    #region 内容添加
    public void AddParagraph(string content, float fontsize)
    {
      SetFont(fontsize);
      Paragraph pra = new Paragraph(content, font);
      document.Add(pra);
    }

    /// <summary>
    /// 高级段落添加：支持对齐、间距、行距控制
    /// Alignment: 0=Left, 1=Center, 2=Right
    /// </summary>
    public void AddParagraph(string content, float fontsize, int Alignment, float SpacingAfter, float SpacingBefore, float MultipliedLeading)
    {
      SetFont(fontsize);
      Paragraph pra = new Paragraph(content, font);
      pra.Alignment = Alignment;
      if (SpacingAfter != 0) pra.SpacingAfter = SpacingAfter;
      if (SpacingBefore != 0) pra.SpacingBefore = SpacingBefore;
      if (MultipliedLeading != 0) pra.MultipliedLeading = MultipliedLeading;
      document.Add(pra);
    }

    public void AddImage(string path, int Alignment, float newWidth, float newHeight)
    {
      Image img = Image.GetInstance(path);
      img.Alignment = Alignment;
      if (newWidth != 0)
      {
        img.ScaleAbsolute(newWidth, newHeight);
      }
      else
      {
        // 若未指定宽高，但宽度超出页面，则自动缩放适应
        if (img.Width > PageSize.A4.Width)
        {
          img.ScaleAbsolute(rect.Width, img.Width * img.Height / rect.Height);
        }
      }
      document.Add(img);
    }

    public void AddAnchorReference(string Content, float FontSize, string Reference)
    {
      SetFont(FontSize);
      Anchor auc = new Anchor(Content, font);
      auc.Reference = Reference;
      document.Add(auc);
    }

    public void AddAnchorName(string Content, float FontSize, string Name)
    {
      SetFont(FontSize);
      Anchor auc = new Anchor(Content, font);
      auc.Name = Name;
      document.Add(auc);
    }
    #endregion
  }
}