CODEWITHSUNDEEP
c#asp.net
Bocky
Bocky

Reputation: 483

Getting back variables after a program crashes

I am trying to find a way to get back my previous variable's value so that I can resume my application to it's previous running state before it crashed when I MANUALLY relaunch it. I am currently using a 'config' file that is saved in the project folder. Is there a better way to do this?

Some small parts of my code that I want to save.

if (EventID == WIA.EventID.wiaEventItemCreated)
        {
            if (d != null)
            {
                foreach (Property p in d.Properties)
                {
                    if (p.Name.Equals("Pictures Taken"))
                        Console.WriteLine("Taken");
                }

                wiaImageFile = (WIA.ImageFile)(d.Items[d.Items.Count].Transfer(FormatID.wiaFormatJPEG));
                wiaImageFile.SaveFile(Properties.Settings.Default.FolderNameRaw + "\\" + imageCount + ".jpg");
                imageCount++;//I want to save this count so that I can continue the sequence even after the application crashes
                Pluck.Default.PhotoExistsInDirectory = true;
                FacebookControls fbc = new FacebookControls();
                if(Properties.Settings.Default.UseFB == true)
                    fbc.UploadPhotos();


            }
        }

Upvotes: 2

Views: 181

Answers (3)

Arie
Arie

Reputation: 5373

You can handle UnhandledException, Application_ThreadException and Application.ApplicationExit Event, and try saving your data there:

http://www.switchonthecode.com/tutorials/csharp-tutorial-dealing-with-unhandled-exceptions

As @C. Ross said, user config file is a good choice.

Of course, first you'll have to preserve your application's state in some object during runtime.

Upvotes: 0

ScruffyDuck
ScruffyDuck

Reputation: 2666

I use config files. I also have a global exception handler that catches any exceptions and offers the chance to save any files (including those that the user is working on) before the app closes.

I would also agree with C Ross that you may persist the data that caused the app to fail. Another option that will not get you right back is to persist the settings at regular intervals using a timer or background process. I use this with several backups a bit like the system restore feature in windows.

Upvotes: 0

C. Ross
C. Ross

Reputation: 31848

A config file is a good answer in general. Your other options are usually the registry or the database, but I would argue that a config file is a safer option.

The thing about persisting this information is that it may cause an error again, and if so you'll want to be able to discard it easily. A file (of course stored in user settings space) is perhaps the way to do that. If need be you can instruct the user to delete the file. It's a more complicated fix for a user to access the registry or the database.

Also, you should wrap up your state in an appropriate object, and build initialization logic that initializes the state object and has mechanism for not loading for the config file.

Upvotes: 1

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