Support to convert the HTML to PDF in Xamarin Forms

Question

With the reference of following StackOverflow suggestion,

Convert HTML to PDF in .NET

I tried to convert the HTML file to PDF using HtmlRenderer.PdfSharp but unfortunately it shows compatible error like below,

HtmlRendererCore.PdfSharpCore 1.0.1 is not compatible with netstandard2.0 (.NETStandard,Version=v2.0). Package HtmlRendererCore.PdfSharpCore 1.0.1 supports: netcoreapp2.0 (.NETCoreApp,Version=v2.0)

 HtmlRenderer.Core 1.5.0.5 is not compatible with monoandroid90 (MonoAndroid,Version=v9.0). Package HtmlRenderer.Core 1.5.0.5 supports:
  - net20 (.NETFramework,Version=v2.0)
  - net30 (.NETFramework,Version=v3.0)
  - net35-client (.NETFramework,Version=v3.5,Profile=Client)
  - net40-client (.NETFramework,Version=v4.0,Profile=Client)
  - net45 (.NETFramework,Version=v4.5)      

HtmlRendererCore.PdfSharpCore 1.0.1 is not compatible with monoandroid90 (MonoAndroid,Version=v9.0). Package HtmlRendererCore.PdfSharpCore 1.0.1 supports: netcoreapp2.0 (.NETCoreApp,Version=v2.0)     

And I tried with wkhtmltopdf too but it throws similar error in android and other platform projects.

My requirement is to convert the HTML file to PDF file only (no need to view the PDF file, just to save it in local path).

Can anyone please provide suggestions?

Note : Need open source suggestion :)

Awaiting for your suggestions !!!

Support to convert the HTML to PDF in Xamarin Forms

Answer 1

You can read the HTML as a stream and store it into local like below,

public static class FileManager
{
    public static async Task<MemoryStream> DownloadFileAsStreamAsync(string url)
    {
        try
        {
            var stream = new MemoryStream();
            using (var httpClient = new HttpClient())
            {
                var downloadStream = await httpClient.GetStreamAsync(new Uri(url));
                if (downloadStream != null)
                {
                    await downloadStream.CopyToAsync(stream);
                }
            }

            return stream;
        }
        catch (Exception exception)
        {
            return null;
        }
    }

    public static async Task<bool> DownloadAndWriteIntoNewFile(string url, string fileName)
    {
        var stream = await DownloadFileAsStreamAsync(url);
        if (stream == null || stream.Length == 0)
            return false;

        var filePath = GetFilePath(fileName);

        if (!File.Exists(filePath))
            return false;

        File.Delete(filePath);

        // Create file.
        using (var createdFile = File.Create(filePath))
        {
        }

        // Open and write into file.
        using (var openFile = File.Open(filePath, FileMode.Open, FileAccess.ReadWrite))
        {
            stream.WriteTo(openFile);
        }

        return true;
    }

    public static string GetFilePath(string fileName)
    {
        var filePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), fileName);
        return filePath;
    }

    public static void WriteAsText(string filePath, string contents)
    {
        File.WriteAllText(filePath, contents);
    }

    public static string ReadAsText(string filePath)
    {
        return File.ReadAllText(filePath);
    }
}

You can read a stored pdf file and displayed using webview like below,

private async void HtmlToPDF()
{
    await FileManager.DownloadAndWriteIntoNewFile("https://www.google.co.in/?gws_rd=ssl", "SavePDF.pdf");
    var filePath = FileManager.GetFilePath("SavePDF.pdf");
    var pdfString = FileManager.ReadAsText(filePath);

    var webView = new WebView
    {
        Source = new HtmlWebViewSource
        {
            Html = pdfString
        }
    };

    this.Content = webView;
}

And the output below,

Likewise, you can save HTML as PDF and do what you want..