Webclient.downloadfile exception-handling

The ServiceException constructor accepts two parameters: the first parameter is the response body returned by the downstream service. The second parameter is the HTTP status code. Now you need to update UserService. Change the fetchUser method:. That's cool because you want to start handling these errors gracefully.

What gives? The point of that catch block is to catch anything not caught by the filter. It's the last stand. It's the Alamo. And when it does catch that exception, it creates a new ServiceException and throws it back. Pay attention to the first catch block. It catches ServiceException.

That should hopefully shed some light on the error assuming there is something there. If that doesn't help, this is what the documentation here says that a WebException means in this context:.

I also tried without avail download data and write bytes to file. I verified the byte array was the right size after download. What is the second argument that you are giving it? If you are giving it a folder instead of a file, that could cause this error. This class makes it possible to easily download web pages for testing. First, to use the WebClient class you need to either use the fully specified name System. WebClient or include the System. Net namespace.

This example creates a new WebClient object instance and sets its user agent. Byte arrays. Example 2. Example 3. Process Tip: You can write a console program that accesses a specific URL and then stores it in a log file. Time downloads. Try Here: It reads the command-line argument and writes the parameters to the screen.

Main args Catch Finally Then: It downloads the page up to times. It averages the total milliseconds elapsed and prints this to the screen as well. C program that times web page downloads using System; using System. Diagnostics; using System. White; Console. WriteLine " PageTimeTest: times web pages" ; Console.

ResetColor ; Console. Do an initial run to prime the cache. TotalMilliseconds ; Console. WriteLine ex. Then specify the URL on the command-line in the shortcut. GZIP headers. Performance-oriented web sites use GZIP compression for transferring pages. The WebClient doesn't send that be default and MSDN warns that some web servers will return a error if user-agent isn't set. If your request requires an optional header, you must add the header to the Headers collection.

For example, to retain queries in the response, you must add a user-agent header. Also, servers may return Internal Server Error if the user agent header is missing. You could wrap the whole thing in a for loop that goes That way if there's an exception, the break gets skipped and the app tries again. But that seems to be more of a band-aid to me; I'd spend more time figuring out exactly why things are going wrong.

If you want to remove all the "try while blah else until rethrow whatever" code from the business logic of your app, you could define an extension method like. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. C webClient.