I was wondering what exceptions I should protect myself against when using WebClient.DownloadString
.
Here's how I'm currently using it, but I'm sure you guys can suggest better more robust exception handling.
For example, off the top of my head:
What is the preferred way to handle these cases and throw the exception to the UI?
public IEnumerable<Game> FindUpcomingGamesByPlatform(string platform)
{
string html;
using (WebClient client = new WebClient())
{
try
{
html = client.DownloadString(GetPlatformUrl(platform));
}
catch (WebException e)
{
//How do I capture this from the UI to show the error in a message box?
throw e;
}
}
string relevantHtml = "<tr>" + GetHtmlFromThisYear(html);
string[] separator = new string[] { "<tr>" };
string[] individualGamesHtml = relevantHtml.Split(separator, StringSplitOptions.None);
return ParseGames(individualGamesHtml);
}
If you catch WebException
, it should handle most cases. WebClient
and HttpWebRequest
throw a WebException
for all HTTP protocol errors (4xx and 5xx), and also for network level errors (disconnection, host not reachable, etc)
How do I capture this from the UI to show the error in a message box?
I'm not sure I understand your question... Can't you just show the exception message?
MessageBox.Show(e.Message);
Don't catch the exception in FindUpcomingGamesByPlatform
, let it bubble up to the calling method, catch it there and show the message...