Visual Basic.NET, an example of using HTTPWebRequest object

Posted by Daniel - 736 Views

vbnet, httpwebrequest, httpwebrequest object, httpwebrequest example, webclient, webclient object On the other article which you can view it here, I had described how to use the WebClient object to download resources from the internet. But you do not have enough control with the WebClient if you need to do something more. This time we’re going explore the other more flexible object related to the internet download process.

This object called HttpWebRequest. It’s located under the System.Net namespace. With this object you will have more control over the process, such as the HTTPVersion and the KeepAlive property.

I am not good in describing things, especially in English, so lets get to the point. Below is an example procedure called GetImageData() . This procedure will try to download images from the internet based on the suplied URL.

Private Sub GetImageData(ByVal strURL As String)
Dim myHttpWebRequest As HttpWebRequest
Dim ImageData As Bitmap
Dim strSavePath As String = “downloadedimg.jpg”
Try
myHttpWebRequest = CType(WebRequest.Create(strURL), HttpWebRequest)
myHttpWebRequest.KeepAlive = False
myHttpWebRequest.ProtocolVersion = HttpVersion.Version10
If Trim(strURL) <> “” Then
Dim myHttpWebResponse As HttpWebResponse = CType(myHttpWebRequest.GetResponse(), HttpWebResponse)
ImageData = New Bitmap(Image.FromStream(myHttpWebResponse.GetResponseStream))
ImageData.Save(strSavePath, System.Drawing.Imaging.ImageFormat.Jpeg)
ImageData.Dispose()
myHttpWebResponse.Close()
End If
Catch e As Exception
MsgBox(“ERROR: “ & e.Message)
Finally

End Try
End Sub

Demo project is included, but it’s different with the example procedure above since I use Thread in this demo project. Do not worry, its a simple one.

Download Demo Project (72 KB)

__________________________

The following posts are programmatically considered as related to the current post by YARPP Plugin:

Related posts brought to you by Yet Another Related Posts Plugin.

share this article

This post as PDFPosted in: Programming - January 2008

Latest from Programming

Get my Full Feed Here or you can subscribe to one of my category based feeds below:

Latest Blog Entries

Neighbours and Friends

Comments - Thanks Guys :)

Therese Lachance: Hi, Any idea how to have ContuttoPDF fetch the correct page language?
Marlena Albu: Super Blog, Dude! I am constantly on the watch for new and interesting sites and postings about audio equipment… which is what...
tresloukadu: yo how did u fixed when the tags shows <? and it shows < “& l t ; ” ?? please send me an email.
Sean: This is a great piece of code and thanks for adding the updates. Sean’s last blog post: Not All Text Message Marketing Is Created...
rodhy: Thank for your code, it very usefull for me. best regard.