void UpdateComponent_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
// e.Error is always null to enable passing back the UserState to the caller.
UpdateComponentArgs result = (UpdateComponentArgs)e.Result;
UpdateComponentCompletedEventArgs updateComponentResult;
if (result.Error != null)
{
updateComponentResult = new UpdateComponentCompletedEventArgs(result.Component,
null,
result.UserState,
result.Error);
}
else
{
updateComponentResult = new UpdateComponentCompletedEventArgs(result.Component,
result.UpdateInfo,
result.UserState,
null);
}
// Signal async callers.
if (UpdateComponentCompleted != null)
{
UpdateComponentCompleted(this, updateComponentResult);
}
}
static void UpdateComponent_DoWork(object sender, DoWorkEventArgs e)
{
UpdateComponentArgs args = e.Argument as UpdateComponentArgs;
if (args == null)
{
throw new ArgumentException("e");
}
try
{
Trace.WriteLine(String.Format("Updating component {0} at {1}.",
args.Component.Assembly,
args.Component.UpdateInfoUrl));
WebRequest request = WebRequest.CreateDefault(new Uri(args.Component.UpdateInfoUrl));
using (WebResponse response = request.GetResponse())
{
using (Stream stream = response.GetResponseStream())
{
XPathDocument doc = new XPathDocument(stream);
XPathNavigator nav = doc.CreateNavigator();
XPathNavigator updateUrl = nav.SelectSingleNode("/updateInfo/updateUrl/text()");
XPathNavigator description = nav.SelectSingleNode("/updateInfo/description/text()");
XPathNavigator updateArticle = nav.SelectSingleNode("/updateInfo/updateArticle/text()");
XPathNavigator version = nav.SelectSingleNode("/updateInfo/version/text()");
args.UpdateInfo = new UpdateInfo(updateUrl != null ? updateUrl.Value.Trim() : null,
description != null ? description.Value.Trim() : null,
updateArticle != null ? updateArticle.Value.Trim() : null,
version != null ? new Version(version.Value) : null);
}
}
}
catch (Exception ex)
{
Trace.WriteLine(String.Format("Error updating component {0} at {1}: {2}",
args.Component.Assembly,
args.Component.UpdateInfoUrl,
ex));
args.Error = ex;
}
e.Result = args;
}
public void UpdateComponentAsync(UpdateableComponent component, object userState)
{
UpdateComponentArgs args = new UpdateComponentArgs();
args.Component = component;
args.UserState = userState;
Trace.WriteLine(String.Format("Starting update of component {0}, UserState={1}.",
args.Component.Assembly,
args.UserState ?? "(null)"));
BackgroundWorker bgw = new BackgroundWorker();
bgw.WorkerSupportsCancellation = false;
bgw.WorkerReportsProgress = false;
bgw.DoWork += UpdateComponent_DoWork;
bgw.RunWorkerCompleted += UpdateComponent_RunWorkerCompleted;
bgw.RunWorkerAsync(args);
}
