public void Download(string localPath)
{
byte[] metadataHash = HashAttachmentMetadata(Name, Comment, DisplayName, Length);
if (null == CQSession)
{
throw new InvalidOperationException("CQSession == NULL");
}
// [teyang] TODO: validation on localPath
if (File.Exists(localPath))
{
File.Delete(localPath);
}
OAdEntity aRecord = CQWrapper.GetEntity(CQSession, EntityDefName, EntityDispName);
OAdAttachmentFields aAllAttFields = CQWrapper.GetAttachmentFields(aRecord);
bool attachmentFound = false;
for (int attFieldsIndex = 0;
attFieldsIndex < CQWrapper.AttachmentsFieldsCount(aAllAttFields);
attFieldsIndex++)
{
object ob = (object)attFieldsIndex;
OAdAttachmentField aAttField = CQWrapper.AttachmentsFieldsItem(aAllAttFields, ref ob);
string fieldName = CQWrapper.GetAttachmentFieldName(aAttField);
if (!CQStringComparer.FieldName.Equals(fieldName, this.FieldName))
{
// not the hosting attachment field, try next one
continue;
}
// attachment field is found, now look for the attachment
OAdAttachments aAttachments = CQWrapper.GetAttachments(aAttField);
OAdAttachment aAttachment = null;
for (int attachmentIndex = 0;
attachmentIndex < CQWrapper.AttachmentsCount(aAttachments);
attachmentIndex++)
{
object obIndex = (object)attachmentIndex;
aAttachment = CQWrapper.AttachmentsItem(aAttachments, ref obIndex);
string name;
string comment;
string dispName;
int fileSize;
CQWrapper.GetAttachmentMetadata(aAttachment, out name, out comment, out dispName, out fileSize);
byte[] hash = HashAttachmentMetadata(name, comment, dispName, (long)fileSize);
if (HashProducer.CompareMD5(metadataHash, hash) == 0)
{
attachmentFound = true;
break;
}
}
if (attachmentFound)
{
Debug.Assert(null != aAttachment, "null == aAttachment");
CQWrapper.LoadAttachment(aAttachment, localPath);
}
// we've checked the host att field already, no need to proceed
break;
}
if (!attachmentFound)
{
// [teyang] TODO: typed exception, AttachmentNotFound conflict handling
throw new Exception(string.Format("attachment '{0}' is not found", Name));
}
}