Silverlight 4 Beta Networking. Part 1 - WebClient and XML | mtaulty

A set of short screencasts providing a "tour" of the network capabilites in the Silverlight 4 beta. We'll look at raw HTTP access, socket access and WCF capabilities.

In this video, we take a look at doing a simple HTTP GET for an XML file with the WebClient API and then reading that with LINQ to XML.

The next video in this series is here.

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BigDubb

Feb 19, 2010 at 11:59 AM

Mike,

Thanks for the exmple on how to use WebClient and asynchronous operations from the client. I do however have a question re: this. The web client seems like a great tool by which to use to get media from a site and allow a user to download. however, with the save dialog box doesn't allow itself to be invoked from a non-user initiated event, which contradicts the async approach.

Any recomendations on how to work around this without having to prompt a user multiple times?
mtaulty Mike Taulty
Feb 20, 2010 at 4:38 PM
Hi BigDubb,

Are you saying that you can't;
1. Prompt the user for a file to save to.
2. Capture the file stream they choose.
3. Begin async download via WebClient.
4. On download complete, write downloaded contents to FileStream from step (2) above.
5. Dispose dialog.
I seem to remember having problems trying to write to this kind of FileStream from a background thread but I'm not sure if I've seen a particular issue doing 1-5 above ( although I haven't gone off and explicitly written the code to test it yet ).

Mike.
Mike Greenway
Mar 01, 2010 at 11:26 AM
Mike's Videos are always very helpful for people like myself - self taught and still learning.
- He always starts at the beginning - assuming I know little.
- He remembers what it is like to "not know" and answers the question I have before I ask them
- the pace is just right and the level of detail is right on
- Best of all - he uses USABLE examples
There are many good programmers but few good teachers

Thank you Mr. Taulty

Mike Greenway
mtaulty Mike Taulty

Mar 03, 2010 at 11:00 AM

Thank you Mr. Greenway - very kind & glad you found these useful

Mike.
mtaulty Mike Taulty

Mar 19, 2010 at 8:14 AM

A quick note on these videos - they have become a little less relevant with the release of the Silverlight RC.

Be wary of changes that happened between the beta and the RC. Not every video will be affected but some definitely are.
Jon Bushby

Mar 22, 2010 at 4:45 AM

Real shame webClient still has no support for credentials. Just tried RC and it's still not there.
mtaulty Mike Taulty

Mar 26, 2010 at 5:09 PM

Jon,

Not sure what you mean - WebClient does have support for credentials. Off the top of my head - if you're on the Browser stack then it'll on use default credentials but if you're on the Client stack it can either use default/prompt or take supplied credentials based on the UseDefaultCredentials property.

Is that not what you're seeing?

Mike.
sam_salt

Dec 02, 2010 at 10:09 PM

Hi Jon,
Hope you are doing well.
I am developing a solution in WP7 with CRM.
As you know that to access any data in CRM you need to provide user credentials.
So I provide it in the following way.

WebClient Download = new WebClient ();

NetworkCredential creds = new NetworkCredential("username", "password", "domainname" );

Download.Credentials = creds;

Download.DownloadStringCompleted += new DownloadStringCompletedEventHandler

(Download_DownloadStringCompleted);

Download.DownloadStringAsync(new Uri http://servername:5555/organizationname/XRMServices/2011/OrganizationData.svc/LeadSet?$select=FirstName

));

private void Download_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)

{

string Any = e.Result.ToString();

}
}

{

if (e.Error == null
)
Sujeet

Jan 27, 2011 at 12:06 PM

can we create silverlight 4.0 pie chart using XML data file?