web端生成pdf
作者：互联网
背景：之前生成pdf一直是直接把html代码通过iTextSharp.text.pdf转成pdf,但是一旦html样式稍微复杂就会错乱，比如input标签不会展示，边框也不会展示，只能展示table这些，所以需要通过其它办法。
一开始是直接搞了个窗体程序做尝试，思路是通过WebBrowser打开html截取图片，注意html需要设置好宽高，否则会以很小的窗口打开，截图会不全。
但是后面想迁移到web项目上发现，web项目没法引用using System.Windows.Forms;从而无法使用WebBrowser。我是直接的把这个dll文件拷到web项目，然后强制引用，最后可以了，一开始虽然可以用WebBrowser，但是运行会报错，看网上通过把WebBrowser另起一个线程，并做一些设置就可以了。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using iTextSharp.text;
using iTextSharp.text.pdf;
using System.IO;
using System.Windows.Forms;
using System.Drawing;
using System.Threading;
namespace ISPR.Common
{
public class PDFConvert
{
public WebBrowser webBrowser = null;
public string PDFPath = "";
/// <summary>
/// 将含有特殊样式的html(例如含有input标签)先转成图片，再从图片转成pdf,注意html宽高需要设置好，否则WebBrowser打开后转成图片会显示不全
/// </summary>
/// <param name="html"></param>
/// <param name="pdfFilePath"></param>
public void ConvertImgToPDF(String html, String pdfFilePath)
{
var t = new Thread(()=>
{
PDFPath = pdfFilePath;
webBrowser = new WebBrowser();
webBrowser.ScriptErrorsSuppressed = true; //防止脚本异常跳出弹窗
//是否显式滚动条
webBrowser.ScrollBarsEnabled = false;
//加载 html
webBrowser.DocumentText = html;
//页面加载完成执行事件
webBrowser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(webBrowser_DocumentCompleted);
while (webBrowser.ReadyState != System.Windows.Forms.WebBrowserReadyState.Complete)
{
System.Windows.Forms.Application.DoEvents(); //避免假死，若去掉则可能无法触发 DocumentCompleted 事件。
}
});
t.SetApartmentState(ApartmentState.STA);
t.Start();
//t.Join(); //阻塞当前线程，等待子线程执行完成
//while(t.IsAlive)
//{
//}
}
public void webBrowser_DocumentCompleted(object sender, EventArgs e)//这个就是当网页载入完毕后要进行的操作
{
//获取解析后HTML的大小
System.Drawing.Rectangle rectangle = webBrowser.Document.Body.ScrollRectangle;
int width = rectangle.Width;
int height = rectangle.Height;
//设置解析后HTML的可视区域
webBrowser.Width = width;//宽高可能需要针对每个html css写好宽高，不然WebBrowser获取的宽高可能会很小
webBrowser.Height = height;
Bitmap bitmap = new System.Drawing.Bitmap(width, height);
webBrowser.DrawToBitmap(bitmap, new System.Drawing.Rectangle(0, 0, width, height));
//设置图片文件保存路径和图片格式，格式可以自定义
//string filePath = AppDomain.CurrentDomain.BaseDirectory + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".png";
//bitmap.Save(filePath, System.Drawing.Imaging.ImageFormat.Png);
if (System.IO.File.Exists(PDFPath))
{
File.Delete(PDFPath);
}
//创建PDF
FileStream fileStream = new FileStream(PDFPath, FileMode.Create);
byte[] result = CreatePDF(bitmap, width, height);
fileStream.Write(result, 0, result.Length);
fileStream.Close();
fileStream.Dispose();
webBrowser = null;
}
public byte[] CreatePDF(Bitmap bitmap, int width, int height)
{
using (MemoryStream ms = new MemoryStream())
{
Document doc = new Document(new iTextSharp.text.Rectangle(0, 0, width, height), 3, 3, 3, 3); // 左右上下
PdfWriter writer = PdfWriter.GetInstance(doc, ms);
writer.CloseStream = false;
doc.Open();
iTextSharp.text.Image img = iTextSharp.text.Image.GetInstance(bitmap, System.Drawing.Imaging.ImageFormat.Png);
img.ScalePercent(100); // 放缩比例
doc.Add(img); // 添加图片对像
doc.Close();
return ms.ToArray();
}
}
/// <summary>
/// 将html转成pdf,复杂样式或者含有input等标签无法渲染出效果
/// </summary>
/// <param name="html"></param>
/// <param name="pdfFilePath"></param>
/// <param name="rotate"></param>
public void ConvertToPDF(String html, String pdfFilePath, bool rotate = false)
{
//Create a byte array that will eventually hold our final PDF
Byte[] bytes;
//Boilerplate iTextSharp setup here
//Create a stream that we can write to, in this case a MemoryStream
using (var ms = new MemoryStream())
{
//Create an iTextSharp Document which is an abstraction of a PDF but **NOT** a PDF
using (var doc = new Document())
{
//Create a writer that's bound to our PDF abstraction and our stream
if(rotate)
doc.SetPageSize(iTextSharp.text.PageSize.A4.Rotate());
using (var writer = PdfWriter.GetInstance(doc, ms))
{
//Open the document for writing
doc.Open();
/**************************************************
* Example #2 *
* *
* Use the XMLWorker to parse the HTML. *
* Only inline CSS and absolutely linked *
* CSS is supported *
* ************************************************/
//XMLWorker also reads from a TextReader and not directly from a string
//using (var srHtml = new StringReader(html))
//{
// //Parse the HTML
// iTextSharp.tool.xml.XMLWorkerHelper.GetInstance().ParseXHtml(writer, doc, srHtml);
//}
byte[] data = Encoding.UTF8.GetBytes(html);//字串轉成byte[]
MemoryStream msInput = new MemoryStream(data);
iTextSharp.tool.xml.XMLWorkerHelper.GetInstance().ParseXHtml(writer, doc, msInput, null, Encoding.UTF8, new UnicodeFontFactory());
doc.Close();
}
}
//After all of the PDF "stuff" above is done and closed but **before** we
//close the MemoryStream, grab all of the active bytes from the stream
bytes = ms.ToArray();
}
//Now we just need to do something with those bytes.
//Here I'm writing them to disk but if you were in ASP.Net you might Response.BinaryWrite() them.
//You could also write the bytes to a database in a varbinary() column (but please don't) or you
//could pass them to another function for further PDF processing.
System.IO.File.WriteAllBytes(pdfFilePath, bytes);
}
}
public class UnicodeFontFactory : FontFactoryImp
{
private static readonly string arialFontPath = Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory,
"Template/Font/arialuni.ttf");//arial unicode MS是完整的unicode字型。
private static readonly string bkt_Path = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Fonts),
"KAIU.TTF");//標楷體
public override iTextSharp.text.Font GetFont(string fontname, string encoding, bool embedded, float size, int style, BaseColor color,
bool cached)
{
//可用Arial或標楷體，自己選一個
BaseFont baseFont = BaseFont.CreateFont(arialFontPath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
return new iTextSharp.text.Font(baseFont, size, style, color);
}
}
}
标签：web,System,生成,iTextSharp,html,webBrowser,using,new,pdf 来源： https://www.cnblogs.com/stubborn-donkey/p/15718327.html