/// <summary>
/// Get the Length of the Http Download.
/// </summary>
/// <param name="ftpWebOperation">Web Operation.</param>
/// <param name="username">Http Login Username.</param>
/// <param name="password">Http Login Password.</param>
/// <param name="ftpMode">Ftp Transfer Mode.</param>
/// <exception cref="ArgumentNullException">Throws if resourceUri is null.</exception>
public long GetFtpDownloadLength(IFtpWebOperation ftpWebOperation, string username, string password, FtpType ftpMode)
{
if (ftpWebOperation == null) throw new ArgumentNullException("ftpWebOperation", "Argument 'httpWebOperation' cannot be null.");
_ftpWebOperation = ftpWebOperation;
_ftpWebOperation.WebOperationProgress += OnHttpWebOperationProgress;
_ftpWebOperation.OperationRequest.CachePolicy = new RequestCachePolicy(RequestCacheLevel.NoCacheNoStore);
SetFtpMode(ftpWebOperation.FtpOperationRequest, ftpMode);
SetNetworkCredentials(_ftpWebOperation.OperationRequest.Request, username, password);
return _ftpWebOperation.GetDownloadLength();
}
