/// <summary>
/// Downloads the file at <see cref="linkToVersionXml"/> and attempts to deserialize it into <see cref="Sys.LastCheckedVersion"/>.
/// Uses the download queue so this happens asynchronously. <see cref="UpdateCheckCompleted"/> is raised when the download is complete.
/// </summary>
public void CheckForUpdates()
{
string path = Path.Combine(Sys.PathToTempFolder, "version.xml");
Directory.CreateDirectory(Sys.PathToTempFolder);
DownloadItem download = new DownloadItem()
{
Links = new List <string>()
{
LocationUtil.FormatHttpUrl(linkToVersionXml)
},
SaveFilePath = path,
Category = DownloadCategory.AppUpdate,
ItemName = $"{ResourceHelper.Get(StringKey.CheckingForUpdatesAt)} {linkToVersionXml}"
};
download.IProc = new Install.InstallProcedureCallback(e =>
{
bool success = (e.Error == null && e.Cancelled == false);
if (success)
{
try
{
Sys.LastCheckedVersion = Util.Deserialize <AvailableUpdate>(path);
}
catch (Exception ex)
{
Sys.LastCheckedVersion = Sys.LastCheckedVersion ?? new AvailableUpdate(); // if currently null then initialize new instance
Sys.Message(new WMessage()
{
Text = $"{ResourceHelper.Get(StringKey.FailedToCheckForUpdatesAt)} {linkToVersionXml}: {ex.Message}", LoggedException = ex
});
}
}
else
{
Sys.LastCheckedVersion = Sys.LastCheckedVersion ?? new AvailableUpdate();
Sys.Message(new WMessage()
{
Text = $"{ResourceHelper.Get(StringKey.FailedToCheckForUpdatesAt)} {linkToVersionXml}", LoggedException = e.Error
});
}
UpdateCheckCompleted?.Invoke(success);
});
Sys.Downloads.AddToDownloadQueue(download);
}
/// <summary>
/// Raises the UpdateCheckCompleted event.
/// </summary>
/// <param name="e"></param>
protected virtual Task OnUpdateCheckCompleted(UpdateCheckEventArgs e)
{
UpdateCheckCompleted?.Invoke(this, e);
return(Task.FromResult(false));
}