Delphi
Delphi

Streams

I know the TSaveToStream etc. but i cant get the stuff working as i want..

in need a Sample of where you like select files and Add the to a Data File, and how to get in contact with them,
like putting 10 exe files in a dat file, and be able to run the apps..

LVL 2

brainwareAsked: 1998-06-16

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LVL 5

ronit051397Commented: 1998-06-17

This is something I found somewhere, Hope this helps:

14. Appending Files

Q:
Does anyone have a procedure/advice/whatever for adding several files
onto one file, then separating them back into the original files /w
filenames, properties, and everything? I was thinking of using the
Append() procedure, but that's for text files, and I'm working with
binary files (compressed, encrypted, what have you).

A:
What I would do is this:

First I create a TFileStream.

Then Write to it a blank but a fixed length header block .

This header block can contain anything you want to keep in
there; such as starting pos of each 'file', their lenths,
file names, copyright info etc.

Initially you can just write a blank header block to act
as place holder (you'll fill it up later)

Then create as many TMemoryStream as you have files/data/whatever.

Then using MyMemoryStream.SaveToStream(MyFileStream) write every
one of those MemoryStreams into the FileStream. Making a note of
MyFileStream.Posotion and MyMemoryStream.Size.

Havin filled your MyFileStream with data, you can now set

FileStream,Position := 0
and fill up the header block you had rserved in the first step.

Retrieving each data block is simply a reverse of this.

[kanca@ibm.net]

LVL 1

michaueCommented: 1998-06-17

Let me see if I understand you correctly.

You want

1. the user to be able to select files and then your program must write the locations of the files into a data file
2. the program to read this data file at a later stage and display it as a pick list to the user.
3. the user to pick one of the listed files and then run it from within your program

???

LVL 2

brainwareAuthor Commented: 1998-06-17

I want to copy the files into a DATA file, like a WAD file..
and be able to use the files in hmm WAD file,
like this: make a WAD!!! file with 10 jpeg or bmp pics, and be able to get info from the
wad file of whats in it, and be able to view the pics..

dont have to be pics... but somthing not only text.

hope u can do it.. now im being nice.. +pts

LVL 1

michaueCommented: 1998-06-17

Nope, you've lost me ...

Hope you find an answer ... you should, this is a pretty good site

Have Fun

Elfrieda :)

LVL 1

Socrates050697Commented: 1998-06-17

I thik this is what you need :-

1. Create a new TFilestream

2. Add a header to it showing what files are going to be stored in the DAT file. (I've done this before by creating a new component - THeader, which has some string properties. Being a component you can just stream it out into the TFilestream)

3. Load the Bitmaps (or whatever) using a TMemorystream object.
4. Stream the TMemorystream to the TFilestream
5. Repeat steps 3 and 4 for each file.

To then extract the files, you have to read the header and then read each of the files and save the one you want as a file on its own. It can then be used as normal.

Socrates.