/// <summary>
/// Called when a version check operation has been performed sucessfully.s
/// </summary>
/// <commondoc select='All/Methods/EventRaisers[@Params="+EventArgs"]/*' params='EventName=VersionCheckSuccessful' />
protected virtual void OnVersionCheckSuccessful(VersionCheckSuccessfulEventArgs e)
{
if (e == null)
{
throw new ArgumentNullException();
}
this.VersionCheckSuccessful?.Invoke(this, e);
}
/// <summary>
/// Beings connecting to the update server asynchronously and raises either the <see cref="VersionCheckSuccessful" />
/// or <see cref="VersionCheckError" /> event when done.
/// </summary>
/// <remarks>
/// <para>
/// The download of the data is performed asynchronously by using a <see cref="BackgroundWorker" /> object. <br />
/// Multiple calls of this method at once can lead in a possible <see cref="NotSupportedException" />,
/// because one instance of this class is not able to handle multiple version check operations at the same time. <br />
/// </para>
/// <note type="implementnotes">
/// Use the <see cref="IsVersionChecking" /> property to check whether an aynchronous version check operation is
/// already in progress before calling this method multiple times.
/// </note>
/// <note type="implementnotes">
/// Use the <see cref="AbortVersionCheck" /> method to cancel an asynchronous version check operation.
/// </note>
/// </remarks>
/// <exception cref="WebException">
/// Error on connecting to server or downloading data or both <see cref="Update_UpdateInfoPage" /> and
/// <see cref="Update_UpdateInfoPageAlt" /> constants contain an invalid URL.
/// </exception>
/// <exception cref="InvalidOperationException">
/// Another asynchronous version check operation is already in progress by this instance.
/// </exception>
/// <commondoc select='IDisposable/Methods/All/*' />
/// <seealso cref="VersionCheckSuccessful">VersionCheckSuccessful Event</seealso>
/// <seealso cref="VersionCheckError">VersionCheckError Event</seealso>
/// <seealso cref="IsVersionChecking">IsVersionChecking Property</seealso>
/// <seealso cref="AbortVersionCheck">AbortVersionCheck Method</seealso>
public void BeginVersionCheck()
{
if (this.IsDisposed)
{
throw new ObjectDisposedException("this");
}
if (this.IsVersionChecking)
{
throw new InvalidOperationException();
}
this.currentVersionCheckWorker = new BackgroundWorker();
this.currentVersionCheckWorker.WorkerSupportsCancellation = true;
this.currentVersionCheckWorker.DoWork += delegate(object sender, DoWorkEventArgs e) {
if (e.Cancel)
{
return;
}
var arguments = (Tuple <string[], Version>)e.Argument;
string[] urlsToCheck = arguments.Item1;
Version currentAppVersion = arguments.Item2;
Exception error = null;
Version mostRecentVersion = null;
string infoMessage = null;
string criticalMessage = null;
// Work through all available servers to check for a new version.
using (WebClient webClient = new WebClient()) {
for (int i = 0; i < urlsToCheck.Length; i++)
{
if (e.Cancel)
{
return;
}
try {
byte[] data = webClient.DownloadData(string.Format(CultureInfo.InvariantCulture, urlsToCheck[i], currentAppVersion));
using (MemoryStream dataStream = new MemoryStream(data)) {
XmlDocument versionCheckData = new XmlDocument();
versionCheckData.Load(dataStream);
if (versionCheckData.DocumentElement == null)
{
throw new FormatException("The update site has returned invalid data.");
}
XmlNode newestVersionNode = versionCheckData.DocumentElement["NewestVersion"];
XmlNode infoMessageNode = versionCheckData.DocumentElement["InfoMessage"];
XmlNode criticalMessageNode = versionCheckData.DocumentElement["CriticalMessage"];
if ((newestVersionNode == null) || (criticalMessageNode == null))
{
throw new FormatException("The update site has returned invalid data.");
}
Version versionNumberFromThisServer;
try {
versionNumberFromThisServer = new Version(newestVersionNode.InnerText);
} catch (Exception exception) {
throw new FormatException("The update site has returned invalid data.", exception);
}
// Make sure that this server didn't return an older version number than another server.
if ((mostRecentVersion != null) && (versionNumberFromThisServer < mostRecentVersion))
{
continue;
}
mostRecentVersion = versionNumberFromThisServer;
criticalMessage = criticalMessageNode.InnerText;
if (infoMessageNode != null)
{
infoMessage = infoMessageNode.InnerText;
}
}
} catch (Exception exception) {
error = exception;
}
}
}
// We don't want to throw an Exception if we got the data we needed from at least one server.
if (mostRecentVersion != null)
{
error = null;
}
VersionCheckSuccessfulEventArgs successfulResultData = null;
if (error == null)
{
successfulResultData = new VersionCheckSuccessfulEventArgs((currentAppVersion < mostRecentVersion), mostRecentVersion, criticalMessage, infoMessage);
}
e.Result = new Tuple <Exception, VersionCheckSuccessfulEventArgs>(error, successfulResultData);
};
this.currentVersionCheckWorker.RunWorkerCompleted += delegate(object sender, RunWorkerCompletedEventArgs e) {
try {
var result = (Tuple <Exception, VersionCheckSuccessfulEventArgs>)e.Result;
if (result.Item1 != null)
{
this.OnVersionCheckError(new ExceptionEventArgs(result.Item1));
}
else
{
this.OnVersionCheckSuccessful(result.Item2);
}
} finally {
if (this.currentVersionCheckWorker != null)
{
this.currentVersionCheckWorker.Dispose();
this.currentVersionCheckWorker = null;
}
}
};
this.currentVersionCheckWorker.RunWorkerAsync(new Tuple <string[], Version>(
new[] { UpdateManager.Update_UpdateInfoPage, UpdateManager.Update_UpdateInfoPageAlt },
(Version)this.Environment.AppVersion.Clone()));
}
