Good coding practice when saving data to files in .net

Question

To give a bit of a background.

I have created an application that allows users to save settings and then recall the settings at a later date. To do this I have created some serializable objects. I have gotten this to work using the BinaryFormatter without much trouble.

Where I start to run into problems is when I upgrade the software and add new settings. Now my serializable objects do not match and so I have to update the files. I have done this successfully for a few versions. But to do this I try deserializing the file and if it throws an exception, I try with the next version. . .and then the next. . .and then the next. . . until I find the right one. Then I have to write conversion functions for each of old versions to convert it into the newest version. I did create a "revision" file as well, so I can just check up front what version they have and then upgrade it, but I still have to keep a lot of different "versions" alive and write the conversion functions for all of them. . . which seems inherently messy to me and prone to bloat later on down the line if I keep going this route.

There has to be a better way to do this, I just am not sure how.

Thanks

Answer 1

You need to write a serialization binder to resolve assemblies.

For settings, I use a Dictionary<string, byte[]> to save to file. I serialize the dictionary and all is well. When I add new settings, I provide a default setting if not found in the settings file.

Also, if you are adding fields to a serialized object, you can decorate with [Optional].