Converting HTML to PDF in C# is an easy task with our API. Today we’ll be going over the functions in this library and we’ll show you code examples in C# that help you turn HTML into PDF.

Our HTML to PDF library works on any platform that has a HTTP connection and supports the following functions for HTML to PDF conversion and enhancing of the PDF:

1. General options such as page format, margins, single page PDF creation etc
2. Protection options such as password protection, encryption and rights management
3. Watermarking or stamping

Basic API usage in C#

In order to use our API to get a PDF you just send a HTTP request with the right information. It’s like typing a URL in the browser address bar. The URL that you use contains the parameters that are the commands that control the API. In it’s simplest form you only pass an API key and a URL and we’ll then return the PDF based on the settings that you have defaulted in your members area.

The HTTP request for getting ‘http://www.google.com’ as PDF looks like this:

https://api.htm2pdf.co.uk/urltopdf?apikey=yourapikey&url=http://www.google.com

In C# you’d code this as follows:

string apiKey = "yourapikey";
string url = "http://www.google.com";

using (var client = new WebClient())
{
client.QueryString.Add("apikey", apiKey);
client.QueryString.Add("url", url);
client.DownloadFile("http://api.htm2pdf.co.uk/urltopdf", @"c:\temp\mypdf.pdf");
}

So you don’t need to install any libraries or nothing. This works out of the box as long as you have subscribed to our simple HTML to PDF API and use your API key.

Additional options for HTML to PDF conversion in C#

As we described earlier, your members area has quite a few defaults that you can easily control there. So if you always need the same page format, margins, header, footer etc etc – you can just edit them there very easily. If you want to have some additional power to control each and every single PDF then you’ll use the additional options, which we’ll describe now.

General options

The table below shows all general options you can add to the HTTP request in order to change the layout of the PDF.

Encryption and protection options

The table below shows the options you have to encrypt the PDF and use protection and rights management options.

Watermarking and stamping

If you’d like to watermark or stamp your PDF you can do so with any image that you provide. We’ll add it to your PDF on every page automaticly. We consider stamping to be the same as watermarking, but then with an opacity of 1 (meaning fully opague).

The table below shows the parameters you can pass to control the watermark on your PDF.

Example with additional options in C#

Now let’s look at what happens if we want to pass additional parameters to control the PDF. In our initial example we were using the C# WebClient() object and then specified two parameters that we added to the query string: apikey & url. Since we have seen the other parameters now we can simple select the ones we want and add those to the query string as well.

So let’s say we want to protect our PDF with password ‘htm2pdf’ and we also would like to watermark it with the logo of our service (who wouldn’t want that?). We’ll use an opacity of 0.5 to make it half transparant and we’ll rotate it 50 degrees and put it on position 100, 100.

We would then do the following in C#:

string apiKey = "yourapikey";
string url = "http://www.google.com";
string userpass = "htm2pdf";
string wm = "http://www.htm2pdf.co.uk/img/logo.png";
string wm_opac = "0.5";
string wm_angle = "50";
string wm_x = "100";
string wm_y = "100";
using (var client = new WebClient()) {
client.QueryString.Add("apikey", apiKey);
client.QueryString.Add("url", url);
client.QueryString.Add("userpass", userpass);
client.QueryString.Add("wm", wm);
client.QueryString.Add("wm_opac", wm_opac);
client.QueryString.Add("wm_angle", wm_angle);
client.QueryString.Add("wm_x", wm_x);
client.QueryString.Add("wm_y", wm_y);
client.DownloadFile("http://api.htm2pdf.co.uk/urltopdf", @"c:\temp\mypdf.pdf");
}

Conclusion on the PDF C# library

As you can see the HTML to PDF API is very easy-to-use in C# and will work right off the bat without installing anything. If you’d like to learn more about all the options then please see the full documentation on the HTML to PDF API. If you think this is awesome then feel free to sign up now!

So you want to convert HTML to PDF in C#? Well – you’ve come to the right place. We’ve made our HTML to PDF API so easy that you’ll be converting any URL to PDF in C# in a matter of minutes.

Our API works by sending a HTTP request with the parameters for the conversion. There’s no library or anything for you to install. You’ll only need a valid API key, which you can get by signing up for our service. In this article we assume your API key is “yourapikey” and we’ll use this in the sample code.

The sole purpose of the code is to send a HTTP request that looks like this:

https://api.htm2pdf.co.uk/urltopdf?apikey=yourapikey&url=http://www.google.com

As you can see you send us a request with just the API key and the URL and in return we’ll send you the PDF. We’ll use the settings in your members area for the conversion. If you want to adjust these you can add parameters to the URL to indicate how you want to do the conversion. We’ll get to that later.

Now suppose you want to do the above URL to PDF conversion in C#. The code you’ll be using will be the following:

string apiKey = "yourapikey";
string url = "http://www.google.com";

using (var client = new WebClient())
{
client.QueryString.Add("apikey", apiKey);
client.QueryString.Add("url", url);
client.DownloadFile("http://api.htm2pdf.co.uk/urltopdf", @"c:\temp\mypdf.pdf");
}

This will get the PDF and store it in the file ‘mypdf.pdf’ in your temp directory.

Adding PDF conversion options in C#

If you want to change the options for the conversion in C#, you can just add extra parameters to the query string and the API will obey your orders. You can find an overview of all the different parameters you can pass in the description of the HTML to PDF API.

For now let’s assume you want to watermark the PDF with our logo and rotate it 45 degrees. You’d then add the correct watermarking parameters to the query string and that’s all there is to it!

Your code would look something like this:

string apiKey = "yourapikey";
string url = "http://www.google.com";
string wm = "http://www.htm2pdf.co.uk/img/logo.png";
string wm_angle = "45";
using (var client = new WebClient())
{
client.QueryString.Add("apikey", apiKey);
client.QueryString.Add("url", url);
client.QueryString.Add("wm", wm);
client.QueryString.Add("wm_angle", wm_angle);
client.DownloadFile("http://api.htm2pdf.co.uk/urltopdf", @"c:\temp\mypdf.pdf");
}

We think this should get you converting HTML to PDF in C# over the next 10 minutes. All you need now is a valid API key, which you can get here. If you want to more about the HTML to PDF API and what all the different conversion options are, then go to the extensive documentation.