listing contents in a folder

thank you sir for your valuable effort..
sir,
How can I use this on a windows application.I have tried it on console application.window is coming .If we give an input it wil coming back to the program.

This will read all files in a directory and extract information into 4 lists that you can use. Note that the lists can contain duplicate values (e.g. fatigue is a symptom for multiple diseases).

The program reads a file and uses a switch to determine between header and content. If a header is detected, it will set the header 'type'. If content is detected, it will add the content line to one of the lists depending on the current header type.

    class Program
    {
        enum HEADINGTYPE
        {
            BASICS,
            PRESENTATION,
            CAUSES,
            EXAMINATION,
            NOTYETDEFINED
        }

        static void Main(string[] args)
        {
            string[] strFiles = System.IO.Directory.GetFiles(".\\diseases");
            List lstFiles = strFiles.ToList();
            lstFiles.Sort();

            // create lists to hold info
            List lstBasics = new List();
            List lstExamination = new List();
            List lstPresentation = new List();
            List lstCauses = new List();
           
            // loop through the files
            for (int filecnt = 0; filecnt < lstFiles.Count; filecnt++)
            {
                // set heading type to not defined
                HEADINGTYPE hdt = HEADINGTYPE.NOTYETDEFINED;

                // read file
                using (System.IO.TextReader rdr = System.IO.File.OpenText(lstFiles[filecnt]))
                {
                    string line;
                    while ((line = rdr.ReadLine()) != null)
                    {
                        switch (line)
                        {
                            case "BASICS":
                                hdt = HEADINGTYPE.BASICS;
                                break;
                            case "CLINICAL PRESENTATION":
                                hdt = HEADINGTYPE.PRESENTATION;
                                break;
                            case "CLINICAL EXAMINATION":
                                hdt = HEADINGTYPE.EXAMINATION;
                                break;
                            case "CAUSES":
                                hdt = HEADINGTYPE.CAUSES;
                                break;
                            default:
                                switch (hdt)
                                {
                                    case HEADINGTYPE.BASICS:
                                        lstBasics.Add(line);
                                        break;
                                    case HEADINGTYPE.CAUSES:
                                        lstCauses.Add(line);
                                        break;
                                    case HEADINGTYPE.EXAMINATION:
                                        lstExamination.Add(line);
                                        break;
                                    case HEADINGTYPE.PRESENTATION:
                                        lstPresentation.Add(line);
                                        break;
                                    default:
                                        // the heading type is not set yet
                                        break;
                                } // end_of_switch(hdt)

                                break;

                        } // end_of_switch(line)
                    }
                }  // end_of_using (System.IO.TextReader rdr= System.IO.File.OpenText(lstFiles[filecnt]))
            }

            lstBasics.Sort();
            lstPresentation.Sort();
            lstExamination.Sort();
            lstCauses.Sort();

            Console.WriteLine("== basics");
            for (int cnt = 0; cnt < lstBasics.Count; cnt++)
            {
                Console.WriteLine(lstBasics[cnt]);
            }
            Console.WriteLine("== presentation");
            for (int cnt = 0; cnt < lstPresentation.Count; cnt++)
            {
                Console.WriteLine(lstPresentation[cnt]);
            }
            Console.WriteLine("== examination");
            for (int cnt = 0; cnt < lstExamination.Count; cnt++)
            {
                Console.WriteLine(lstExamination[cnt]);
            }
            Console.WriteLine("== causes");
            for (int cnt = 0; cnt < lstCauses.Count; cnt++)
            {
                Console.WriteLine(lstCauses[cnt]);
            }
            Console.WriteLine("== done");


            Console.ReadLine();
        }
    }

here I am pasting the one file content.please check it.
BASICS
•Abnormal deficiency of sweat
•Other characteristics malaise, easyfatiguability, headache, nausea, warmth, dry skin, tachcardia
CLINICAL PRESENTATION
•Skin deficient sweat
•Malaise
•Easy fatiguability
•Headache
•Nausea
•Warmth
•Dry skin
CLINICAL EXAMINATION
•Skin deficient sweat
•Tachycardia
CAUSES
•Senile skin
•Radiodermatitis
•Acrodermatitis chronica atrophica
•Scleroderma
•Lichen sclerosis et atrophica
•Spinal cord lesions
•Fabry's disease
•Quinacrine toxicity
•Miliaria
•Sympathectomy

I don't see an attached file; might be me as I'm very new to this site, so I'm not sure where to look for it.

thanks for your reply... I am having no of files containing some information regarding diseases.Each file containing the same heading like clinical presentation,clinical examination and causes.If the user want to search by clinical presentation,the listbox should fill with the content under the heading clinical presentation from all files..have you got my point???here I am attaching the sample data files.Please check this...

So you basically want something like this?

        headingA    headingB    headingC
file1   abc         def         xyz  
file2   123         456         890
file3   1a1         2b2         3c3    

I can't advise on how to pull the specific data for a column (heading) without more information about it. If that's your problem, you have to provide some sample data.

I don't understand what you mean by "particular heading". But below might get you started

        static void Main(string[] args)
        {
            string[] strFiles = System.IO.Directory.GetFiles("c:\\");
            List lstFiles = strFiles.ToList();
            lstFiles.Sort();

            for (int filecnt = 0; filecnt < lstFiles.Count; filecnt++)
            {
                Console.WriteLine(System.IO.File.ReadAllText(lstFiles[filecnt]));
            }
        }

It gets the files in a directory and stores them into an array; you can write your own sorting algorithm for alphabetical ordering. I convert the string array to a list so it can be sorted.

The for-loop is where the processing of the files is done; for you to implement.