字典的通用/ DRY方式<string, T>

Question

I have a CSV parser that takes the text line-by-line and parses it to values. I'm trying to put these values in a Dictionary<string, T> and return it, where T is a descendant of class CharacterStatElement . I do know what class I want T to be when I parse the CSV, but I don't want to have to rewrite/copypaste the same parser function several times to cover each Type that I want to return from it.

Should I be writing a Generic Method for the whole thing (and if so, how do I declare that in the Method and return?) or should I be doing some other pattern here?

Further info on the CharacterStatElement: Each of the child classes contains several fields that I figure out in the parsing using reflection. Each of the child classes has different values, but they ought to all be parsed the same way. Also, this only happens once per button click, not on a loop, so speed isn't an issue. And extracting the meat of the method to wrap it in non-generic methods doesn't do me much good, because most of the parsing method is tied to what the intended Type is by my use of reflection.

Answer 1

You can use a generic method. In order to use reflection on the type parameter you can get a Type object using typeof(T) . That way you can instantiate that type and set properties dynamically. This is a rather bad case for generics. If you just used object instead of T everything would pretty much work the same way. That's a sign generics are not needed.

You also could pass in a "strategy" into the generic function that knows how to convert the raw parsed fields (probably a string[] ) into a T . That strategy would be a Func<string[], T> . That way there is no reflection at all and this is a clean use case for generics.

Or, make the CSV parser return an IEnumerable<string[]> and deal with the conversion to T outside of the CSV parsing method.

Answer 2

I would suggest that the CharacterStatElement class have a method that knows how to parse the remaining of the input line. Each derived class is overridden to perform its specific parsing process. Add any helper methods to the base class so minimize coding needed in the derived classes.

Then you process each line of the CSV file in the following way. Parse the start that gives you the information you need to decide on the correct class for parsing the whole line. Then create an instance of the correct derived class and pass in the line for processing. Then add to your global dictionary the values. Simple.