How to use Reflection instead of switch case - C#

Question

I have edited my previous question because of lack of information.

I have written a class named ReaderFactory where I create a Method GetAReader(string filename).This method returns a reader using its file-name extension. I used switch-case to select the specific reader.But my instructor suggested me to use reflection instead of switch-case.I have started to learn reflection and got stuck on its behavior. How can I implement reflection instead of switch-case in my code? GetAReader method is given below :

 
        public static IReader GetAReader(string _fileName)
        {
            fileName = _fileName;
            fileExtension = Path.GetExtension(fileName);

        switch (fileExtension) 
        {
            case ".txt":
                     TextFileReader _textReader = new TextFileReader(fileName);
                         _textReader.ReadData();
                      return _textReader;

            case ".pdf":
                         PDFReader _pdfReader = new PDFReader(fileName);
                         _pdfReader.ReadData();
                         return _pdfReader;
            case ".doc":
                        //reader initialize
            case ".rtf":
                         //reader initialize
            case ".docx":
                        //reader initialize
            case ".jpg":
                        //reader initialize


        }

        return null;
    }

http://stackoverflow.com/questions/1859902/in-3-minutes-what-is-reflection — Yuval Itzchakov, May 26 '14 at 10:46
"Please repeat to me a largee part of the documentation. I am too lazy to read the documentation, but I promise I will not be too lazy to read it if you copy/paste it". — TomTom, May 26 '14 at 10:46
http://stackoverflow.com/questions/1458256/why-is-the-use-of-reflection-in-net-recommended — Mohamed, May 26 '14 at 10:47
I urge you not to read about reflection as a beginner, its "powers" may encourage you to use it for areas where you should apply core concepts of the language — Sayse, May 26 '14 at 10:47
I see "beginner" and "reflection" six words apart. That does not bode well... — flindeberg, May 26 '14 at 11:00

score 4 · Answer 1 · answered May 26 '14 at 10:47

4

Reflection is something very complicated, but can be used for a wide variety of things. Some examples:

Reading properties by the specifying the name.
Load an assembly and get all the types of it.
Read attributes

To make it very short, with reflection you have the power to decompile any .NET code to C# / VB or any other IL language.

I suggest you have a look at telerik's decompiler (that's a tool that let you view source code of dll's). Than you have an idea what reflection is.

Alo, here's some documentation to get you started: http://msdn.microsoft.com/en-us/library/f7ykdhsy.aspx

answered May 26 '14 at 10:47

Complexity

5,682
6
41
84

I edited my question. can you please elaborate those question. – fyasir May 26 '14 at 16:23
Don't understand me wrong, but there are already a lot of articles on Reflection. Can you explain me why you need it? I ask this because reflection is quite expensive and if there's a built in .NET solution, that might be much quicker. I will give you the explanations you need, but I just want to avoid that u use code which requires unneeded resources. – Complexity May 26 '14 at 16:29
I have written a class named Reader.I used switch-case for selecting the file extension.As there are lots of file type my instructor suggested me to use reflection instead of switch-case.I started reading about reflection and got stuck on dynamically load assembly files.So can you please explain me How can I use reflection instead of switch-case? – fyasir May 26 '14 at 16:43
Ok, please edit your original question where you show your code and what the code is supposed to do. That way you will get better answers on your questions. – Complexity May 26 '14 at 16:44
Thanks for the suggestion.I am editing my original question – fyasir May 26 '14 at 17:00
Thanks. I will try to answer later today. – Complexity May 26 '14 at 17:04
I'm sorry but I don't know what your prof is saying. Can you tell me where he would use reflection and I what context? Since reflection is very wide it's important that we know the context. Reading attributes, get types, ... Anyway. I will post some examples still today about reflection to get you started. – Complexity May 26 '14 at 18:05
My instructor told me to use reflection instead of switch-case portion. – fyasir May 26 '14 at 18:24
I don't see how. I'm sorry. – Complexity May 26 '14 at 18:25
1

But I've looked around on the net and come accross to this post on StackOverflow. http://stackoverflow.com/questions/4234421/method-factory-case-vs-reflection It's a discussion to see what's faster a switch or reflection. A switch will always be faster, but maybe it's a good idea to read that post. And don't hesitate to come back if you have any further questions. – Complexity May 26 '14 at 18:29

How to use Reflection instead of switch case - C#

1 Answers1