/// <summary>
/// Creates a new transfer job.
/// </summary>
/// <param name="displayName">The display name.</param>
/// <param name="remoteUrl">The remote URL.</param>
/// <param name="localFile">The local file.</param>
/// <param name="priority">The priority.</param>
/// <exception cref="System.InvalidOperationException">An unexpected exception occurred trying to create the job.</exception>
public IDownloadJob CreateJob(string displayName, string remoteUrl, string localFile, DownloadPriority priority = DownloadPriority.Normal)
{
if (!Path.IsPathRooted(localFile))
{
localFile = new FileInfo(localFile).FullName;
}
var targetDir = Path.GetDirectoryName(localFile);
if (!Directory.Exists(targetDir))
{
Directory.CreateDirectory(targetDir);
}
if (File.Exists(localFile))
{
File.Delete(localFile);
}
IBackgroundCopyManager bitsManager = null;
IBackgroundCopyJob bitsJob = null;
var id = Guid.Empty;
try {
bitsManager = (IBackgroundCopyManager) new BackgroundCopyManager();
bitsManager.CreateJob(displayName, BG_JOB_TYPE.BG_JOB_TYPE_DOWNLOAD, out id, out bitsJob);
// ***
// SET UP BITS JOB SETTINGS--TIMEOUTS/RETRY ETC
// SEE THE FOLLOWING REFERENCES:
// ** http://msdn.microsoft.com/library/default.asp?url=/library/en-us/bits/bits/IBackgroundCopyJob2_setminimumretrydelay.asp?frame=true
// ** http://msdn.microsoft.com/library/default.asp?url=/library/en-us/bits/bits/IBackgroundCopyJob2_setnoprogresstimeout.asp?frame=true
// ** http://msdn.microsoft.com/library/default.asp?url=/library/en-us/bits/bits/bg_job_priority.asp
// ***
// in constant set to 0; this makes BITS retry as soon as possible after an error
bitsJob.SetMinimumRetryDelay(DownloadJob.DefaultMiniumRetryDelay);
// in constant set to 5 seconds; BITS will set job to Error status if exceeded
bitsJob.SetNoProgressTimeout(DownloadJob.DefaultNoProgressTimeout);
bitsJob.SetPriority((BG_JOB_PRIORITY)(int)priority);
bitsJob.AddFile(remoteUrl, localFile);
bitsJob.SetNotifyFlags((uint)(
BG_JOB_NOTIFICATION_TYPE.BG_NOTIFY_JOB_ERROR |
BG_JOB_NOTIFICATION_TYPE.BG_NOTIFY_JOB_MODIFICATION |
BG_JOB_NOTIFICATION_TYPE.BG_NOTIFY_JOB_TRANSFERRED));
var job = new DownloadJob(id, displayName, remoteUrl, localFile, priority);
// Set the notify interface to get BITS events
bitsJob.SetNotifyInterface(job);
return(job);
} catch (COMException cex) {
string error;
bitsManager.GetErrorDescription(cex.ErrorCode, 1033, out error);
throw new InvalidOperationException(error, cex);
} finally {
if (bitsJob != null)
{
Marshal.ReleaseComObject(bitsJob);
}
if (bitsManager != null)
{
Marshal.ReleaseComObject(bitsManager);
}
}
}
/// <summary>
/// Asynchronous download method implementation.
/// </summary>
/// <param name="task">The DownloadTask to process.</param>
public void BeginDownload(DownloadTask task)
{
IBackgroundCopyManager backGroundCopyManager = null;
IBackgroundCopyJob backgroundCopyJob = null;
Guid jobID = Guid.Empty;
try
{
// create the manager
backGroundCopyManager = (IBackgroundCopyManager) new BackgroundCopyManager();
// If the job is already finished, just return
if (CheckForResumeAndProceed(backGroundCopyManager, task, out backgroundCopyJob))
{
return;
}
if (backgroundCopyJob != null)
{
// if CheckForResumeAndProceed connected to an ongoing BITS job
// wire up our notify interface to forward events to the client
backgroundCopyJob.SetNotifyInterface(this);
backgroundCopyJob.SetNotifyFlags((uint)(
BG_JOB_NOTIFICATION_TYPE.BG_NOTIFY_JOB_ERROR |
BG_JOB_NOTIFICATION_TYPE.BG_NOTIFY_JOB_MODIFICATION |
BG_JOB_NOTIFICATION_TYPE.BG_NOTIFY_JOB_TRANSFERRED)
);
}
else
{
// use utility function to create the job.
CreateCopyJob(
backGroundCopyManager,
out backgroundCopyJob,
ref jobID,
task.DownloadItem.OwnerItemId,
task.DownloadItem.Enclosure.Description, task);
// Save the jobId in the task
task.JobId = jobID;
// Prepare the job to download the manifest files
PrepareJob(backgroundCopyJob, task);
// Set the notify interface to get BITS events
backgroundCopyJob.SetNotifyInterface(this);
backgroundCopyJob.SetNotifyFlags((uint)(
BG_JOB_NOTIFICATION_TYPE.BG_NOTIFY_JOB_ERROR |
BG_JOB_NOTIFICATION_TYPE.BG_NOTIFY_JOB_MODIFICATION |
BG_JOB_NOTIFICATION_TYPE.BG_NOTIFY_JOB_TRANSFERRED)
);
// Fire our download start event
OnDownloadStarted(new TaskEventArgs(task));
// Initiate the BITS Job
backgroundCopyJob.Resume();
}
}
catch (Exception e)
{
// if exception, clean up job
OnJobError(task, backgroundCopyJob, null, e);
}
finally
{
if (null != backgroundCopyJob)
{
Marshal.ReleaseComObject(backgroundCopyJob);
}
if (null != backGroundCopyManager)
{
Marshal.ReleaseComObject(backGroundCopyManager);
}
}
}