我想通过将HTML内容传递给函数来生成PDF。我已经为此使用了iTextSharp,但它在遇到表和布局时表现不佳。
有没有更好的办法?
我想通过将HTML内容传递给函数来生成PDF。我已经为此使用了iTextSharp,但它在遇到表和布局时表现不佳。
有没有更好的办法?
当前回答
下面是一个使用iTextSharp将html + css转换为PDF的示例(iTextSharp + iTextSharp .xmlworker)
using iTextSharp.text;
using iTextSharp.text.pdf;
using iTextSharp.tool.xml;
byte[] pdf; // result will be here
var cssText = File.ReadAllText(MapPath("~/css/test.css"));
var html = File.ReadAllText(MapPath("~/css/test.html"));
using (var memoryStream = new MemoryStream())
{
var document = new Document(PageSize.A4, 50, 50, 60, 60);
var writer = PdfWriter.GetInstance(document, memoryStream);
document.Open();
using (var cssMemoryStream = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(cssText)))
{
using (var htmlMemoryStream = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(html)))
{
XMLWorkerHelper.GetInstance().ParseXHtml(writer, document, htmlMemoryStream, cssMemoryStream);
}
}
document.Close();
pdf = memoryStream.ToArray();
}
其他回答
HTML到PDF的转换大多依赖于IE来完成HTML的解析和渲染。这可以打破用户更新他们的IE。这里有一个不依赖IE的。
代码是这样的:
EO.Pdf.HtmlToPdf.ConvertHtml(htmlText, pdfFileName);
像许多其他转换器一样,您可以传递文本、文件名或Url。结果可以保存到文件或流中。
你可以使用WebBrowser控件的另一个技巧,下面是我的完整工作代码
在我的例子中,为文本框控件分配Url
protected void Page_Load(object sender, EventArgs e)
{
txtweburl.Text = "https://www.google.com/";
}
下面是使用线程生成屏幕的代码
protected void btnscreenshot_click(object sender, EventArgs e)
{
// btnscreenshot.Visible = false;
allpanels.Visible = true;
Thread thread = new Thread(GenerateThumbnail);
thread.SetApartmentState(ApartmentState.STA);
thread.Start();
thread.Join();
}
private void GenerateThumbnail()
{
// btnscreenshot.Visible = false;
WebBrowser webrowse = new WebBrowser();
webrowse.ScrollBarsEnabled = false;
webrowse.AllowNavigation = true;
string url = txtweburl.Text.Trim();
webrowse.Navigate(url);
webrowse.Width = 1400;
webrowse.Height = 50000;
webrowse.DocumentCompleted += webbrowse_DocumentCompleted;
while (webrowse.ReadyState != WebBrowserReadyState.Complete)
{
System.Windows.Forms.Application.DoEvents();
}
}
在下面的代码中,我下载后保存pdf文件
private void webbrowse_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
// btnscreenshot.Visible = false;
string folderPath = Server.MapPath("~/ImageFiles/");
WebBrowser webrowse = sender as WebBrowser;
//Bitmap bitmap = new Bitmap(webrowse.Width, webrowse.Height);
Bitmap bitmap = new Bitmap(webrowse.Width, webrowse.Height, PixelFormat.Format16bppRgb565);
webrowse.DrawToBitmap(bitmap, webrowse.Bounds);
string Systemimagedownloadpath = System.Configuration.ConfigurationManager.AppSettings["Systemimagedownloadpath"].ToString();
string fullOutputPath = Systemimagedownloadpath + Request.QueryString["VisitedId"].ToString() + ".png";
MemoryStream stream = new MemoryStream();
bitmap.Save(fullOutputPath, System.Drawing.Imaging.ImageFormat.Jpeg);
//generating pdf code
Document pdfDoc = new Document(new iTextSharp.text.Rectangle(1100f, 20000.25f));
PdfWriter writer = PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
pdfDoc.Open();
iTextSharp.text.Image img = iTextSharp.text.Image.GetInstance(fullOutputPath);
img.ScaleAbsoluteHeight(20000);
img.ScaleAbsoluteWidth(1024);
pdfDoc.Add(img);
pdfDoc.Close();
//Download the PDF file.
Response.ContentType = "application/pdf";
Response.AddHeader("content-disposition", "attachment;filename=ImageExport.pdf");
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.Write(pdfDoc);
Response.End();
}
你也可以参考我最老的帖子了解更多信息:在asp.net web表单中导航到网页被取消了
下面是一个使用iTextSharp将html + css转换为PDF的示例(iTextSharp + iTextSharp .xmlworker)
using iTextSharp.text;
using iTextSharp.text.pdf;
using iTextSharp.tool.xml;
byte[] pdf; // result will be here
var cssText = File.ReadAllText(MapPath("~/css/test.css"));
var html = File.ReadAllText(MapPath("~/css/test.html"));
using (var memoryStream = new MemoryStream())
{
var document = new Document(PageSize.A4, 50, 50, 60, 60);
var writer = PdfWriter.GetInstance(document, memoryStream);
document.Open();
using (var cssMemoryStream = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(cssText)))
{
using (var htmlMemoryStream = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(html)))
{
XMLWorkerHelper.GetInstance().ParseXHtml(writer, document, htmlMemoryStream, cssMemoryStream);
}
}
document.Close();
pdf = memoryStream.ToArray();
}
你可以使用谷歌Chrome打印到pdf功能从它的无头模式。我发现这是最简单但最健壮的方法。
var url = "https://stackoverflow.com/questions/564650/convert-html-to-pdf-in-net";
var chromePath = @"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe";
var output = Path.Combine(Environment.CurrentDirectory, "printout.pdf");
using (var p = new Process())
{
p.StartInfo.FileName = chromePath;
p.StartInfo.Arguments = $"--headless --disable-gpu --print-to-pdf={output} {url}";
p.Start();
p.WaitForExit();
}
如果你需要完美的html pdf渲染,你需要使用商业库。
ExpertPdf Html To Pdf Converter非常容易使用,它支持最新的html5/css3。您可以将整个url转换为pdf:
using ExpertPdf.HtmlToPdf;
byte[] pdfBytes = new PdfConverter().GetPdfBytesFromUrl(url);
或者HTML字符串:
using ExpertPdf.HtmlToPdf;
byte[] pdfBytes = new PdfConverter().GetPdfBytesFromHtmlString(html, baseUrl);
您还可以选择直接将生成的pdf文档保存到磁盘上的文件流。