how can i download a web page from my web app, then reading "title" and "开发者_JAVA百科description" metatag ? Like a web crawler, but in Asp.net and called by ..an asp.net web page ?
Thanks!
You can do a screen scrape of an external URL in .NET using the WebClient
class, which you'll find in the System.Net
namespace. Use the DownloadData
method to download the content from a specified URL. The downloaded data comes down as a byte array, but you can convert this to a string.
The following snippet shows how to use WebClient
to grab the HTML from my blog's homepage, http://scottonwriting.net/sowblog/default.aspx:
// Create a new WebClient instance.
WebClient myWebClient = new WebClient();
// Download the markup from
byte[] myDataBuffer = myWebClient.DownloadData("http://scottonwriting.net/sowblog/default.aspx");
// Convert the downloaded data into a string
string markup = Encoding.ASCII.GetString(myDataBuffer);
Once you have the markup you can use regular expressions or string searching methods to pick out the markup of interest.
Use the HTML Agility Pack and its HTMLWeb
class.
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