Xamarin free HTML or DOC to PDF Conversion - html

Question

I'm currently searching for a library or a way to convert HTML OR DOCX files into PDF on the phone/tab, primarily I'am searching for a way on Android or iOS idk if its a PCL or platform specific approach. I could do this for every Platform independently, because our app requires iOS 8 or android kitkat, both supporting native PDF conversion but i want to do it seamless for the user, so the question is, if anyone has done this before, without loading it into a visible Webview at first or has knowledge of an open not GPL licensed API(can't publish the code), to do this with Xamarin.
I am aware of the possibility to do this online, but I don't want to to be dependent to a online service for this.
Help and ideas are appreciated.

Answer 1

Android Solution:
Call the SafeHTMLToPDF(string html, string filename) via a dependency service like
DependencyService.Get<YOURINTERFACE>().SafeHTMLToPDF(htmlString, "Invoice");
public string SafeHTMLToPDF(string html, string filename)
{
var dir = new Java.IO.File(Android.OS.Environment.ExternalStorageDirectory.AbsolutePath + "/pay&go/");
var file = new Java.IO.File(dir + "/" + filename + ".pdf");
if (!dir.Exists())
dir.Mkdirs();
int x = 0;
while (file.Exists())
{
x++;
file= new Java.IO.File(dir + "/" + filename + "( " + x + " )" + ".pdf");
}
if (webpage == null)
webpage = new Android.Webkit.WebView(GetApplicationContext());
int width = 2102;
int height = 2973;
webpage.Layout(0, 0, width, height);
webpage.LoadDataWithBaseURL("",html, "text/html", "UTF-8" , null);
webpage.SetWebViewClient(new WebViewCallBack(file.ToString()));
return file.ToString();
}
class WebViewCallBack : WebViewClient
{
string fileNameWithPath = null;
public WebViewCallBack(string path)
{
this.fileNameWithPath = path;
}
public override void OnPageFinished(Android.Webkit.WebView myWebview, string url)
{
PdfDocument document = new PdfDocument();
PdfDocument.Page page = document.StartPage(new PdfDocument.PageInfo.Builder(2120 ,3000, 1).Create());
myWebview.Draw(page.Canvas);
document.FinishPage(page);
Stream filestream = new MemoryStream();
FileOutputStream fos = new Java.IO.FileOutputStream(fileNameWithPath, false); ;
try
{
document.WriteTo(filestream);
fos.Write(((MemoryStream)filestream).ToArray(), 0, (int)filestream.Length);
fos.Close();
}
catch
{
}
}
}
And the Way to do it under iOS
public string SafeHTMLToPDF(string html, string filename)
{
UIWebView webView = new UIWebView(new CGRect(0, 0, 6.5 * 72, 9 * 72));
var documents = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
var file = Path.Combine(documents, "Invoice" + "_" + DateTime.Now.ToShortDateString() + "_" + DateTime.Now.ToShortTimeString() + ".pdf");
webView.Delegate = new WebViewCallBack(file);
webView.ScalesPageToFit = true;
webView.UserInteractionEnabled = false;
webView.BackgroundColor = UIColor.White;
webView.LoadHtmlString(html, null);
return file;
}
class WebViewCallBack : UIWebViewDelegate
{
string filename = null;
public WebViewCallBack(string path)
{
this.filename = path;
}
public override void LoadingFinished(UIWebView webView)
{
double height, width;
int header, sidespace;
width = 595.2;
height = 841.8;
header = 10;
sidespace = 10;
UIEdgeInsets pageMargins = new UIEdgeInsets(header, sidespace, header, sidespace);
webView.ViewPrintFormatter.ContentInsets = pageMargins;
UIPrintPageRenderer renderer = new UIPrintPageRenderer();
renderer.AddPrintFormatter(webView.ViewPrintFormatter, 0);
CGSize pageSize = new CGSize(width, height);
CGRect printableRect = new CGRect(sidespace,
header,
pageSize.Width - (sidespace * 2),
pageSize.Height - (header * 2));
CGRect paperRect = new CGRect(0, 0, width, height);
renderer.SetValueForKey(NSValue.FromObject(paperRect), (NSString)"paperRect");
renderer.SetValueForKey(NSValue.FromObject(printableRect), (NSString)"printableRect");
NSData file = PrintToPDFWithRenderer(renderer, paperRect);
File.WriteAllBytes(filename, file.ToArray());
}
private NSData PrintToPDFWithRenderer(UIPrintPageRenderer renderer, CGRect paperRect)
{
NSMutableData pdfData = new NSMutableData();
UIGraphics.BeginPDFContext(pdfData, paperRect, null);
renderer.PrepareForDrawingPages(new NSRange(0, renderer.NumberOfPages));
CGRect bounds = UIGraphics.PDFContextBounds;
for (int i = 0; i < renderer.NumberOfPages; i++)
{
UIGraphics.BeginPDFPage();
renderer.DrawPage(i, paperRect);
}
UIGraphics.EndPDFContent();
return pdfData;
}
}

Answer 2

Frustrated with the existing solutions, I've built some extension methods (OpenSource, MIT Licensed) that convert HTML or the content of a Xamarin.Forms.WebView to a PDF file. Sample usage for WebView to PDF:
async void ShareButton_Clicked(object sender, EventArgs e)
{
if (Forms9Patch.ToPdfService.IsAvailable)
{
if (await webView.ToPdfAsync("output.pdf") is ToFileResult pdfResult)
{
if (pdfResult.IsError)
using (Toast.Create("PDF Failure", pdfResult.Result)) { }
else
{
var collection = new Forms9Patch.MimeItemCollection();
collection.AddBytesFromFile("application/pdf", pdfResult.Result);
Forms9Patch.Sharing.Share(collection, shareButton);
}
}
}
else
using (Toast.Create(null, "PDF Export is not available on this device")) { }
}
}
For a more complete explanation of how to use it, here's a short article: https://medium.com/#ben_12456/share-xamarin-forms-webview-as-a-pdf-a877542e824a?

Answer 3

You can able to convert the HTML to PDF file without any third party library. I am sharing my git repo for future reference.
https://github.com/dinesh4official/XFPDF

Answer 4

Yes, you can convert a Word document to PDF in Xamarin with a few lines of code easily. You need to refer Syncfusion.Xamarin.DocIORenderer from nuget.org
Assembly assembly = typeof(App).GetTypeInfo().Assembly;
// Retrieves the document stream from embedded Word document
Stream inputStream = assembly.GetManifestResourceStream("WordToPDF.Assets.GettingStarted.docx");
string fileName = "GettingStarted.pdf";
// Creates new instance of WordDocument
WordDocument wordDocument = new WordDocument(inputStream,Syncfusion.DocIO.FormatType.Automatic);
inputStream.Dispose();
// Creates new instance of DocIORenderer for Word to PDF conversion
DocIORenderer render = new DocIORenderer();
// Converts Word document into PDF document
PdfDocument pdfDocument = render.ConvertToPDF(wordDocument);
// Releases all resources used by the DocIORenderer and WordDocument instance
render.Dispose();
document.Close();
// Saves the converted PDF file
MemoryStream outputStream = new MemoryStream();
pdfDocument.Save(outputStream);
// Releases all resources used by the PdfDocument instance
pdfDocument.Close();
To know more about this, kindly refer here.