Create Thumbnail from url like Digg in asp.net/C# - asp.net

How I can create a thumbnail from a URL?
For example:
Like on Digg, when I submit a link, Digg choses a Thumbnail from any images on that URL.
Or like Facebook, when I submit a link, I can chose a thumbnail for that link.
So, how I can do that with ASP.Net/C#. I just want to create a thumbnail (not a screenshot of the web page).

To create a screenshot from a web page you need to have an interface to a layout engine like Gecko or Webkit. You may use khtml2png for creating web page screenshots.
To create thumbnails from the web page you have to parse the web page's source, download the image links and resize them to the given thumbnail size.

You can try my C# wrapper for CutyCapt.

Related

Thumbnail image on Facebook can't be uploaded, neither do the metatags work

I'm having an issue concerning the thumbnail from a web page that is being shared on socials (LinkedIn & Facebook). LinkedIn has an easy way to choose whatever image you want as a thumbnail, but Facebook is not working for me as it should even if I upload the desired image as one of the available images.
[The first 5 are automatically generated, the 6th is uploaded. I'm unable to only select the uploaded image, the one I desire to use as a stand-alone thumbnail image.][1]
I've tried to add the desired image to the og metatags (drupal 8), but it still doens't load the right image.
Where should I look further into to find a solution? The metatags on our website or Facebook's uploading system?
Thanks in advance for any help.
[1]: https://i.stack.imgur.com/GFhI9.png

How to Display Scroll, Like and Video on Header on Wordpress Post when Open from Facebook App?

When I check other site, it opens in facebook built-in browswer, with scroll, comment, like, share and video play on the top of the header:
However, when I open my site, it looks different, event my content is the same as them. I don't find video on the header, scroll navigating page on the top, and comment like share at the bottom.
But they both open in Built-in facebook app browser.
We both using Wordpress with the same theme.
It's an instant article which we have to apply via Facebook. Thanks.

Adding a link from an image in wordpress

This seems to be more difficult than it should be.
All I would like to be able to do is add a link from an image on my wordpress site to an external website.
Using the normal media library tools this doesn't seem to be possible so I got the plugin WP Gallery Custom Links
However, even though I added the external link to the Gallery Link URL it still doesn't link.
Is there a more straightforward way to embed a link into an image?
Here is a screenshot of the image editing page:
If you are trying to make an Image clickable and bring you to an external site, click the image, click Edit, under Display settings select link to, custom url, and there you go.
Another way is, when you are adding an image to your site from your Media Library within Wordpress, there is an option "Link to" under Attachment Display Settings.

Embedding links in WordPress 3.6

I am developing a theme for WordPress 3.6 and as far as I know embedded links, like if just place a link into the post for YouTube it should auto embed its self. that's not the case here - would any one know what would cause links from services like YouTube to not embed?
[embed][/embed] doesn't work either...
Make sure the YouTube link is not hyperlinked. If the URL is shown in
your theme’s link color (as the second line in the screenshot below),
then it is hyperlinked. Simply select the whole URL and click the
“Unlink” icon on your Visual Editor toolbar.
Once the URL is unlinked, you will see the link text in black. Make
sure to place the YouTube URL or shortcode on its own line. This
means there should be no character or whitespace before or after the
URL/shortcode.
http://en.support.wordpress.com/shortcodes/
However, beyond those issues you might want to look into. the API that WP uses to embed links from YouTube, Twitter, Flicker...
http://oembed.com/
oEmbed is a format for allowing an embedded representation of a URL on third party sites. The simple API allows a website to display embedded content (such as photos or videos) when a user posts a link to that resource, without having to parse the resource directly.
Unlink the link if it's linked and use the shortcode :
[youtube=http://www.youtube.com/XXXX] and that will work.

How to make dynamic post's preview image for facebook in blogspot.com?

I would like to add post's preview image to facebook Open Graph meta tag.
One possible solution is to use data:blog.postImageThumbnailUrl:
<meta expr:content='data:blog.postImageThumbnailUrl' property='og:image'/>
However, the default post image thumbnail which is created by Blogger is too small (72px × 72px), and it doesn't look really nice when facebook tries to stretch it while creating the post's story based on this image thumbnail (facebook says "all the images referenced by og:image must be at least 200px in both dimensions").
So, the question is:
is there any way to retrieve somehow the image's url from the post's body and insert it into facebook Open Graph meta tag which was mentioned above?
(let's say every post of my blog has image tag inside its body:
http://loveclubhouse.blogspot.com/)
Yes! You can. It's kind of sloppy looking, but functional. Here the og:image property from my blog. As you see it is actually grabbing an image from my Facebook profile:
<meta content='http://sphotos.xx.fbcdn.net/hphotos-ash3/538645_3357819035748_1577184006_2624573_712999292_n.jpg' property='og:image'/>
When you load an image from your photo library in Facebook, you can usually right click on it and select "View Image". When you do that, you'll see the URL to the actual image as it is stored by Facebook. So long as the image is publicly accessible, there won't be any problems.
You can see it in action at my blog if you decide to click Recommend (the current page) or Like (of an individual post). :)

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