一、添加OpenHtmlToPdf，iTextSharp，O2S.Components.PDFRender4NET引用
（1）OpenHtmlToPdf：是一个.NET库（开源的），用于将HTML文档呈现为PDF格式。
github地址：https://github.com/vilppu/OpenHtmlToPdf
（2）iTextSharp：是一个.NET下处理pdf文件的库，提供给pdf文件加水印的功能。
（3）O2S.Components.PDFRender4NET：是一个.NET库，用于将PDF文档呈现为图片。
想要在C#中把html转成PDF,PDF转成图片，首先得要有个C#版的驱动。
通过网络下载或nuget安装，得到OpenHtmlToPdf、iTextSharp、O2S.Components.PDFRender4NET相关的dll，添加到项目中引用。
第一步：在项目中右键，选择管理NuGet程序包
第二步：搜索OpenHtmlToPdf、iTextSharp，选中安装
第三步：下载O2S.Components.PDFRender4NET.dll，在Nuget中没找到，只能自己找资源下载了
下载地址：https://download.csdn.net/download/u011301348/12442663
下载完成后添加dll引用到项目中
通过这三步，在项目中有OpenHtmlToPdf、iTextSharp、O2S.Components.PDFRender4NET的引用，表示添加成功
二、创建PDFTools工具类
/// <summary>
/// PDF工具
/// </summary>
public class PDFTools
{
/// <summary>
/// html转pdf
/// </summary>
/// <param name="html"></param>
/// <param name="watermarkimg">水印图片</param>
/// <returns></returns>
public static string HtmlToPdf(string html, string watermarkimg)
{
var document = Pdf.From(html)
.OfSize(PaperSize.A4) //大小，这里选A4纸大小
.WithGlobalSetting("margin.top", "0.4cm"); //设置全局样式
//此属性的值在32位进程中为4，在64位进程中为8。
if (IntPtr.Size == 4)
{
document = document.WithObjectSetting("load.zoomFactor", "1.5");
}
var result = document.Content();
string filePath = "pdf/" + DateTime.Now.ToString("yyyyMMddHH") + "/";//路径
if (!Directory.Exists(filePath))
{
Directory.CreateDirectory(AppDomain.CurrentDomain.BaseDirectory + filePath);//保存在当前项目跟路径下
}
string fileName = DateTime.Now.ToString("yyyyMMddHHmmssffffff") + ".pdf";
//通过stream把html写入到pdf文件中
FileStream fs = new FileStream(AppDomain.CurrentDomain.BaseDirectory + filePath + fileName, FileMode.Create, FileAccess.Write);
fs.Write(result, 0, result.Length);
fs.Close();
//加水印
string filewatermarkPath = filePath + DateTime.Now.ToString("yyyyMMddHHmmssffffff") + ".pdf";
var res = PDFWatermark(AppDomain.CurrentDomain.BaseDirectory + filePath + fileName, AppDomain.CurrentDomain.BaseDirectory + filewatermarkPath, watermarkimg);
if (res)
{
if (File.Exists(AppDomain.CurrentDomain.BaseDirectory + filePath + fileName))
File.Delete(AppDomain.CurrentDomain.BaseDirectory + filePath + fileName);
return filewatermarkPath;
}
else
return filePath + fileName;
}
/// <summary>
/// PDF转化为图片
/// </summary>
/// <param name="filePath">文件路径</param>
/// <param name="resolution">分辨率</param>
/// <returns></returns>
public static List<string> PDFToIMG(string filePath, float resolution)
{
string imgPath = "pdf/IMG/" + DateTime.Now.ToString("yyyyMMddHH") + "/";
//如果文件夹不存在，则创建
if (!Directory.Exists(imgPath))
{
Directory.CreateDirectory(AppDomain.CurrentDomain.BaseDirectory + imgPath);
}
PDFFile file = PDFFile.Open(filePath);
int pageCount = file.PageCount;
List<string> imgPathList = new List<string>();
for (int i = 0; i < pageCount; i++)
{
string imgName = DateTime.Now.ToString("yyyyMMddHHmmssffffff") + ".jpg";
Bitmap img = file.GetBWPageImage(i, resolution);
img.Save(AppDomain.CurrentDomain.BaseDirectory + imgPath + imgName, System.Drawing.Imaging.ImageFormat.Jpeg);
imgPathList.Add(imgPath + imgName);
}
return imgPathList;
}
/// <summary>
/// pdf加水印
/// </summary>
/// <param name="inputfilepath">模板路径</param>
/// <param name="outputfilepath">导出水印背景后的PDF</param>
/// <param name="ModelPicName">水印图片</param>
/// <returns></returns>
public static bool PDFWatermark(string inputfilepath, string outputfilepath, string ModelPicName)
{
PdfReader pdfReader = null;
PdfStamper pdfStamper = null;
try
{
pdfReader = new PdfReader(inputfilepath);
pdfStamper = new PdfStamper(pdfReader, new FileStream(outputfilepath, FileMode.Create));
PdfGState gs = new PdfGState();
gs.FillOpacity = 0.4f;//透明度
iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance(ModelPicName);
int numberOfPages = pdfReader.NumberOfPages;
//每一页加2个水印,也可以设置某一页加水印
for (int i = 1; i <= numberOfPages; i++)
{
PdfContentByte waterMarkContent = pdfStamper.GetOverContent(i);//内容上层加水印
//PdfContentByte waterMarkContent = pdfStamper.GetUnderContent(i);//内容下层加水印
waterMarkContent.SetGState(gs);
image.SetAbsolutePosition(20, 100);//水印定位坐标
waterMarkContent.AddImage(image);
image.SetAbsolutePosition(20, 300);
waterMarkContent.AddImage(image);
}
//一定要2个循环才会在每一个加上水印，咱也不知道为啥，反正是试了好久试出来的
for (int i = 1; i <= numberOfPages; i++)
{
PdfContentByte waterMarkContent = pdfStamper.GetOverContent(i);//内容上层加水印
//PdfContentByte waterMarkContent = pdfStamper.GetUnderContent(i);//内容下层加水印
waterMarkContent.SetGState(gs);
image.SetAbsolutePosition(20, 100);
waterMarkContent.AddImage(image);
image.SetAbsolutePosition(20, 300);
waterMarkContent.AddImage(image);
}
return true;
}
catch (Exception ex)
{
ex.Message.Trim();
return false;
}
finally
{
if (pdfStamper != null)
pdfStamper.Close();
if (pdfReader != null)
pdfReader.Close();
}
}
}
三、调用
在HomeController中添加一下方法。
1.定义组装html生成pdf文件，并给pdf加水印方法
public string CreatePdf()
{
StringBuilder detail = new StringBuilder();
detail.Append(@"<p><span style='FONT-FAMILY:宋体;BACKGROUND:white;COLOR:#333333'></span></p><p><span style='FONT-FAMILY:宋体;BACKGROUND:white;COLOR:#333333'>pdf商品</span></p>");
detail.Append(@"<table style='WIDTH:280px' height='159' cellspacing='0' cellpadding='0' width='807' align='center' uetable='null' data-sort='sortDisabled'><tbody>");
detail.Append("<tr class='firstRow'>");
detail.Append("<td valign='top' width='47'><p><span style='FONT-SIZE:13px;FONT-FAMILY:宋体;BACKGROUND:white;COLOR:#333333'>序号</span></p></td>");
detail.Append("<td valign ='top' width='83'><p style='TEXT-ALIGN:center'><span style='FONT-SIZE:13px;FONT-FAMILY:宋体;BACKGROUND:white;COLOR:#333333'>商品名称</span></p></td>");
detail.Append("<td valign='top' width='132'><p style='TEXT-ALIGN:center'><span style='FONT-SIZE:13px;FONT-FAMILY:宋体;BACKGROUND:white;COLOR:#333333'>品牌</span></p ></td>");
detail.Append("<td valign='top' width='75'><p style='TEXT-ALIGN:center'><span style='FONT-SIZE:13px;FONT-FAMILY:宋体;BACKGROUND:white;COLOR:#333333'>单位</span></span></p></td>");
detail.Append("<td valign='top' width='50'><p style='TEXT-ALIGN:center'><span style='FONT-SIZE:13px;FONT-FAMILY:宋体;BACKGROUND:white;COLOR:#333333'>规格</span></p></td>");
detail.Append("<td valign='top' width='66'><p style='TEXT-ALIGN:center'><span style='FONT-SIZE:13px;FONT-FAMILY:宋体;BACKGROUND:white;COLOR:#333333'>价格</span></p></td>");
detail.Append("</tr>");
for (int i = 1; i < 100; i++)
{
detail.Append("<tr>");
detail.Append($"<td valign='top' width='47'>{i}</td>");
detail.Append($"<td valign='top' width='83'>商品{i}</td>");
detail.Append($"<td valign='top' width='83'>品牌{i}</td>");
detail.Append($"<td valign='top' width='83'>单位{i}</td>");
detail.Append($"<td valign='top' width='83'>规格{i}</td>");
detail.Append($"<td valign='top' width='83'>价格{i}</td>");
detail.Append("</tr>");
i++;
}
detail.Append("</tbody></table>");
//生成PDF
string html = $"<!DOCTYPE html><html><head><meta charset='UTF-8'><title>pdf</title></head><body>{detail.ToString()}</body></html>";
string pdfPath = PDFTools.HtmlToPdf(html, $"{AppDomain.CurrentDomain.BaseDirectory}/Images/wm.jpeg");
return pdfPath;
}
2.在Index中调用。
public ActionResult Index()
{
string pdfpath = CreatePdf();//生成pdf，加水印
ViewBag.pdfpath = pdfpath;
ViewBag.imgpath = PDFTools.PDFToIMG(AppDomain.CurrentDomain.BaseDirectory + pdfpath, 200);//pdf转图片
return View();
}
3.查看结果
4.浏览器中打开pdf文件效果
5.转换成图片效果
四、代码下载地址
