How do I print an HTML document from a web service?
C#HtmlWeb ServicesPrintingC# Problem Overview
I want to print HTML from a C# web service. The web browser control is overkill, and does not function well in a service environment, nor does it function well on a system with very tight security constraints. Is there any sort of free .NET
library that will support the printing of a basic HTML page? Here is the code I have so far, which does not run properly.
public void PrintThing(string document)
{
if (Thread.CurrentThread.GetApartmentState() != ApartmentState.STA)
{
Thread thread =
new Thread((ThreadStart) delegate { PrintDocument(document); });
thread.SetApartmentState(ApartmentState.STA);
thread.Start();
}
else
{
PrintDocument(document);
}
}
protected void PrintDocument(string document)
{
WebBrowser browser = new WebBrowser();
browser.DocumentText = document;
while (browser.ReadyState != WebBrowserReadyState.Complete)
{
Application.DoEvents();
}
browser.Print();
}
This works fine when called from UI-type threads, but nothing happens when called from a service-type thread. Changing Print()
to ShowPrintPreviewDialog()
yields the following IE script error:
> Error: dialogArguments.___IE_PrintType
is null or not an object.
>
> URL: res://ieframe.dll/preview.dlg
And a small empty print preview dialog appears.
C# Solutions
Solution 1 - C#
You can print from the command line using the following: > rundll32.exe > %WINDIR%\System32\mshtml.dll,PrintHTML > "%1"
Where %1 is the file path of the HTML file to be printed.
If you don't need to print from memory (or can afford to write to the disk in a temp file) you can use:
using (Process printProcess = new Process())
{
string systemPath = Environment.GetFolderPath(Environment.SpecialFolder.System);
printProcess.StartInfo.FileName = systemPath + @"\rundll32.exe";
printProcess.StartInfo.Arguments = systemPath + @"\mshtml.dll,PrintHTML """ + fileToPrint + @"""";
printProcess.Start();
}
N.B. This only works on Windows 2000 and above I think.
Solution 2 - C#
I know that Visual Studio itself (at least in 2003 version) references the IE dll directly to render the "Design View".
It may be worth looking into that.
Otherwise, I can't think of anything beyond the Web Browser control.
Solution 3 - C#
Easy! Split your problem into two simpler parts:
- render the HTML to PDF
- print the PDF (SumatraPDF)
> * -print-to-default $file.pdf
prints a PDF file on a default printer
> * -print-to $printer_name $file.pdf
prints a PDF on a given printer
Solution 4 - C#
If you've got it in the budget (~$3000), check out PrinceXML.
It will render HTML into a PDF, functions well in a service environment, and supports advanced features such as not breaking a page in the middle of a table cell (which a lot of browsers don't currently support).
Solution 5 - C#
I tool that works very well for me is HiQPdf. https://www.hiqpdf.com/
The price is reasonable (starts at $245) and it can render HTML to a PDF and also manage the printing of the PDF files directly.
Solution 6 - C#
Maybe this will help. http://www.codeproject.com/KB/printing/printhml.aspx Also not sure what thread you are trying to access the browser control from, but it needs to be STA
Note - The project referred to in the link does allow you to navigate to a page and perform a print without showing the print dialog.
Solution 7 - C#
I don't know the specific tools, but there are some utilities that record / replay clicks. In other words, you could automate the "click" on the print dialog. (I know this is a hack, but when all else fails...)