I'm brushing up on my VB.NET skills for a future project I will be working on. This application will be very data intensive, requiring 20+ data tables, user supplied images, and possibly even short audio/video files.
I want to be able to save all of this information into a single, external file, so that the user can share what they create with the world.
Ideally, I would like all the text based data to be stored in a database format that I can easily work with, preferably via the entity framework.
Pretty much all the information I'm finding relates to only saving a single text/XML file, and that will not really work for me. Can anyone point me in the proper direction, or suggest a method that will let me save the data?
I'm working inside Visual Studio 2012 Pro, with a Visual Basic Windows Form Application. Please let me know if you need any additional information.
I'll expand my comment to an answer instead.
As previously mentioned this sounds like a zip file. In this you can:
Have a file called databasetables.txt or whatever containing the database tables.
You can have Audio, Video, Images etc in respective folders. This way when you open your file you can just load all files in the Audio folder to get the expected files.
You can have information stored in xmlfiles.
Endless posibilities...
Just keep in mind that you might want to load all this only into the memory of the computer so you dont extract it onto the hard drive.
And you dont have to save the file as .zip to open it as .zip, just select your own cool suffix which will look neat :)
Related
I have a text file. Now I have changed its file type from .txt to .abc. My VB.NET program loads the text into textboxes from that file. After changing the file type, however, other apps like NotePad and Word are able to open and read my .abc file.
Is there any way that only my application will be able to open/read from the file and no other app would be able to do so? What I mean is, suppose I have a PhotoShop document .psd file, no other app, rather that photoshop itself, can open it. How do I make my file unreadable by other apps?
There is no way to prevent an app that you don't develop from opening any file. The extensions are just there for helping us humans, and maybe a bit for the computer to know the default app you select for an extension.
Like you said, a .txt file can be opened by many many apps. You can open a .txt file with Notepad, Firefox, VSCode, and many others.
Same way, a .psd file can be opened by many many apps. You can open that .psd file with Photoshop, but also Notepad, Firefox, and VSCode, and probably the same apps as above.
The difference is which apps can read and understand the file.
In order to make a file not understandable by other apps, you need to make it into a format that cannot recognize, because you planned it "in secret".
Like Visual Vincent said above, you could encrypt the file in a way, or you can have a binary file, that basically only your app knows know to understand.
Since you dont own the app you want the file to be understood by, then you either have to accept that it can be opened by any app that can open files, or you can try to encrypt the file outside the app, or like zipping it with a password, and then decrypting or unzipping when you want to use it.
Firstly, any file can be read unless it is still open by a particular process or service. Even PhotoShop files can be 'read' by NotePad - try it!
So, an attempt at my first answer...
You can try a couple of methods to prevent opening the file, for instance, applying a file lock. As an example, SQL Server .mdf files are locked by the SQL Server service. This happens because the files are maintained in an open state, however; your application would have to remain running to keep these files open. Technically, though, the files can still be copied.
Another way is to set the hidden attribute for the file. This hides the file from the less savvy users, but it will be displayed if the user show's hidden files.
And my second answer: You refer to the format of files by saying only PhotoShop can read or write its own files (not true, but I know what you're saying).
The format of the file must be decided by yourself. You must determine how you are going to store the data that you output from your application. It looks like you have been attempting to write your application data into a text file. Perhaps you should try writing to binary files instead. Binary files, while not encrypted, as suggested by Visual Vincent in the comments to your question, still provide a more tailored approach to storing your data.
Binary files write raw binary data instead of humanised text. For instance, if you write an integer to the file it will appear as a string of four bytes, not your usual 123456789 textual format.
So, you really need to clarify what data you want to write to the file, decide on a set structure to your file (as you also have to be able to read it back in to your application) and then be able to write the information.
I've become stuck at this hurdle. I'm trying to create a database that clients fill in, however the client can set different database paths to view different information in the program. I want to create template databases so should they wish to create a new database it will work with the SQL queries the program uses.
I'm trying to save the templates in to the program so that when a button is clicked, the template file is "downloaded" (copied) to the clients desktop.
Is this even possible?
Thanks
You can open the Resources page of the project properties and add any existing file, including a SQL Server MDF data file. At run time, you can get the data of the file from the appropriate property of My.Resources. The type of the data depends on the type of the file. I'd expect that an MDF file would come back as a Byte array, which you can then write to a file or whatever.
That said, you don't want to make your EXE too big by embedding several sizeable data files in it. You might be better off just using loose files in a subfolder or, if you're determined to use resources, create a satellite assembly, i.e. a DLL that contains just resources.
I've been trying to find a way to store a .wav file in a database (Access) and then retrieve it into Visual Basic 2008 application.
I can do it for an image file, but whatever I've tried for audio files has been a failure so far. I have done a lot of searching in different sites, but it seems that no one has had this need since I haven't found a single site that addresses this.
By the way, I don't want to store a pointer to the file on disk by storing the file directory information. I want the actual contents of the file to be stored in the database, the same way that I am doing with the graphics file. Is it possible to do it? How?
Thanks,
Luis
I'd store the .wav in a local file;
Dim filestring as string = application.startuppath & "\filename.wav"
Use the database to hold the filename, then MCI strings etc. to play it from wherever you stored it before.
However if you're quite sure you want to find it from the directory, I'd send the problem in to daniweb, see if they know.
I need to find a way to automate the process when a user uploads a microsoft project file to a web application I already have created. The process will need to basically use the save as from project to save into a .csv file so I can use this to import the data to an SQL database (this is needed for custom reporting we already have set up using SQL). I need to automate this process because I will be receiving tons of project files, and if the process is automated the users will then be able to instantly see results.
Basically, is there any way to create or run an automated process that will save these project files as .csv files? Even if the csv files are not formatted correctly, I can find a way around that, just need to first get them into .csv files.
Thank you.
edit - the only way i could think of this is to follow the instructions listed below, but
I would then need to automate a process to open the file and hit save so this works... any other suggestions?
http://social.technet.microsoft.com/Forums/en-US/projectprofessional2010general/thread/eea4ca15-0a0b-4c07-9989-87536b961385/
edit 2 - also looking into ways using Microsoft.Office.Interop.MSProject but not finding any luck.
edit 3 0 now using mpxj - the only issue I am having is the following listed below. Converting their example to vb.
Private Shared Function ToEnumerable(ByVal javaCollection As Collection) As EnumerableCollection
Return New EnumerableCollection(javaCollection)
End Function
the error is with EnumberableCollection - visual studio is not picking it up as a valid type - anything I am doing wrong or should substitute?
If you aren't wedded to using MS Project itself to extract data from the project files, you could consider using the MPXJ library. This would allow you to write a simple utility to open the MPP files you are given, extract the data items you are interested in, and write them directly to your database (or an intermediate CSV file, as required). MPXJ comes in Java and .Net flavours, so you can use your preferred language to do the work.
Jon
p.s. Disclaimer: I maintain MPXJ
I'm new at writing code for websites. The website allows users to upload files, such as profile pictures or other pictures. The files are saved in the unix file system and the URLs to find those images are stored in a MySQL database.
It seems like the only way I can let the user upload files is to give write access to anybody using chmod. Otherwise it complains that it doesn't have write permissions. But they shouldn't be able to write whatever they want or overwrite other users stuff. Similarly, to allow users to see images that they have rightful access to, they need read permissions on the file system. But now that means that anybody with the url to that picture can see the image too, correct? That's not what I want.
Is there a solution to this contradiction? Or am I thinking about the problem incorrectly? Thanks for any help.
You need to manage the permissions in your application and not expose arbitrary parts of your local filesystem directly to the clients. Your application should decide what files someone can see or where to write data. You should not trust data (filenames, etc) from your clients...ideally, store files on disk using systematically generated names and store human-readable names in the database.
SunStar9,
Since you are already using a MySQL database to store the URL of the image on the file system, why not just store the image itself as a BLOB (binary large object)?
This is generally a well-accepted design practice for allowing users to upload binary data to a website.
Are you using PHP, Java, Ruby/Rails, or something other to develop your website? Depending on what you are using, there could be file upload/management plugins or modules that will help you develop what you are trying to do if you are certain you want to use the files ystem for storing the image data.