Extract Images From Website – C# Examples

Suppose you are a web developer, graphic designer, researcher, journalist, or student, in a word, a person working on his own project. In that case, you will obviously need images for your project in the development process. To download images from website manually, you spend a very long time. You will have to copy each image URL and then save the image, but you can use Aspose.HTML for .NET library to extract images from website programmatically.

In this article, we look at how to extract from website various types of images by using Aspose.HTML for .NET API. Using our C# library will help you download images from website. It’s better than digging and looking for them manually. Let’s try! Extract images from website programmatically!

Extract Images from Website – C# code

Most pictures in an HTML document are represented using the <img> element. Here is an example of how to use Aspose.HTML for .NET to find images specified by this element. So, to download images from website, you should take a few following steps:

1. Use the HTMLDocument(Url) constructor to create an instance of the HTMLDocument class and pass it the URL of the website from which you want to find images.
2. Use the GetElementsByTagName(“img”) method to collect all <img> elements. The method returns a list of the HTML document’s <img> elements.
3. Use the Select() method to create a distinct collection of relative image URLs and the GetAttribute(“src”) method to extract the src attribute of each <img> element.
4. Create absolute image URLs using the Url class and the BaseURI property of the HTMLDocument class.
5. For each absolute URL, create a request using the RequestMessage(url) constructor.
6. Use the document’s Context.Network.Send(request) method to send the request. The response is checked to ensure it was successful.
7. Finally, if the response was successful, use the File.WriteAllBytes() method to save each image to a local file.

using Aspose.Html;
using Aspose.Html.Net;
using System.IO;
using System.Linq;
...
    // Open a document you want to extract images from
    using var document = new HTMLDocument("https://docs.aspose.com/svg/net/drawing-basics/svg-shapes/");

    // Collect all <img> elements
    var images = document.GetElementsByTagName("img");

    // Create a distinct collection of relative image URLs
    var urls = images.Select(element => element.GetAttribute("src")).Distinct();

    // Create absolute image URLs
    var absUrls = urls.Select(src => new Url(src, document.BaseURI));

    foreach (var url in absUrls)
    {
        // Create an image request message
        using var request = new RequestMessage(url);

        // Extract image
        using var response = document.Context.Network.Send(request);

        // Check whether a response is successful
        if (response.IsSuccess)
        {
            // Save image to a local file system
            File.WriteAllBytes(Path.Combine(OutputDir, url.Pathname.Split('/').Last()), response.Content.ReadAsByteArray());                   
        }
    }

Extract Icons – C# code

Icons are a kind of image in HTML documents that are specified using <link> elements with the rel attribute set to icon. Let’s look at how to extract icons from website using the Aspose.HTML for .NET library:

1. Use the HTMLDocument(Url) constructor to create an instance of the HTMLDocument class and pass it the URL of the website from which you want to extract icons.
2. Use the GetElementsByTagName(“link”) method to collect all <link> elements.
3. To filter out non-icon images, use the Where() method that filters the collection based on the link => link.GetAttribute("rel") == "icon" expression. Thus, the icons collection will contain only links with a rel attribute with the value icon.
4. Use the Select() method to create a distinct collection of relative icon URLs and the GetAttribute(“href”) method to extract the href attribute of each <link> element.
5. Create absolute icon URLs using the Url class and the BaseURI property of the HTMLDocument class.
6. Then, for each absolute URL, create a request using the RequestMessage class.
7. Use the document’s Context.Network.Send(request) method to send the request. The response is checked to ensure it was successful.
8. If the response was successful, use the File.WriteAllBytes() method to save icons to a local file. As a result, you will have a collection of icons from website in your local folder.

using Aspose.Html;
using Aspose.Html.Net;
using System.IO;
using System.Linq;
...
    // Open a document you want to extract icons from
    using var document = new HTMLDocument("https://docs.aspose.com/html/net/message-handlers/");

    // Collect all <link> elements
    var links = document.GetElementsByTagName("link");

    // Leave only "icon" elements
    var icons = links.Where(link => link.GetAttribute("rel") == "icon");

    // Create a distinct collection of relative icon URLs
    var urls = icons.Select(icon => icon.GetAttribute("href")).Distinct();

    // Create absolute icon URLs
    var absUrls = urls.Select(src => new Url(src, document.BaseURI));

    foreach (var url in absUrls)
    {
        // Create a extracting request
        using var request = new RequestMessage(url);

        // Extract icon
        using var response = document.Context.Network.Send(request);

        // Check whether a response is successful
        if (response.IsSuccess)
        {
            // Save icon to a local file system
            File.WriteAllBytes(Path.Combine(OutputDir, url.Pathname.Split('/').Last()), response.Content.ReadAsByteArray());

            Assert.True(File.Exists(Path.Combine(OutputDir, url.Pathname.Split('/').Last())));
        }
    }

You can use these C# examples to automate extracting all images from website, which can be helpful for tasks such as archiving, researching, analyzing web content, or any other application for personal use. Also, this is great for web designers and developers wanting to pull images from sites without diving into the source code.

You can download the complete C# examples and data files from GitHub.

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