I have BLOB field where I store documents from OleContainer (streams). Later on, I can use OleContainer to open and modify document. How I do that:
1. Declare str:TMemoryStream on the Form level
2. On btnOpenClick I create str:TMemoryStream, read the value from BLOB field, put it in OleContainer as stream, open Ole (DoVerb) object, modify it and update OleContainer.
3.Then on btnSaveClick, I use the same stream "str" (created in another procedure but declared on form-level) to update Blob field.
Question/Problem: I noticed that if I try to destroy the "str" (str.Free) after calling myAdoDataSet.Post, it will not post the changes and I got error "dataset not in edit or insert mode". But, if I don't Free the stream then it's fine. ??? Why? Is it safe to do this way, will my "str" object be Killed when I close the form?
Here is the "save to database" code:
if (rst.State=dsEdit) then
//if assigned(str) then str.Free;