How do I print an HTML document from a web service?

Question

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.

Answer 1

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.

Answer 2

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.