Retrieving data in a text file...

Question

Hey all.

Personal life been pretty screwed so am getting back into coding for fun.

I'm creating a program that needs to read data from an external text file, separate the lines (each line contains a series of data) and then grab the values from the line.

My text file structure looks similar to this, and I have the entire contents in a string:

00000,80,9,120
00001,40,2,290
00002,50,7,600

As you can probably see, the first column of data represents the ID/reference number of the row, while the latter 3 columns are actually data values.

I can split the lines up into an array easily enough so it's somewhat like:

data[1] = "00000,80,9,120";
data[2] = "00001,40,2,290";
data[3] = "00002,50,7,600";

But what if I want to actually sort the tags.

Say I want to grab row 2, I'd be matching the string against "^00001".

So say I'm looping through my array, waiting for the string to match with the ID and then boom, it's matched.

I do know the code to do this, but it failed and I got mad, something about an index exceeding its boundaries.

So I'd like to hear your suggestions,

Thanks a lot :D

Answer 1

This may not be the best solution, but it is a starting point :)

//Get string [] which represents each line of text
            //this string[] will be called lines

            Hashtable details = new Hashtable();

            foreach (string strLine in lines)
            {
                string[] csv = strLine.Split(',');
                ArrayList values = new ArrayList();

                //Create arraylist of values
                foreach (string value in csv)
                {
                    values.Add(value);
                }

                //remove first value as this is the id
                values.RemoveAt(0);

                details.Add(csv[0], values);

            }

Answer 2

Cheers, looks pretty good. I'll have a crack at it now. :)


 EDIT: Ok, right. Basically I have no idea what this code is supposed to do. I've used foreach before, but only really in PHP. As a result I dunno what the foreach is doing. We;ll start with the obvious: what is str line? And how do I choose what ID I want to select from? And what will my final variable be (that I want to load into a textbox) Sorry, I'm not so good with the stuff I don't normally use, especially when I haven't written it myself. Thanks a load for your help

Answer 3

Hi,
i hope it helps

 private void button1_Click(object sender, EventArgs e)
        {
           string value=ReadFile(textBox1.Text.ToString().Trim());
           MessageBox.Show(value);
        }
        
        private string ReadFile(string id)
        {
            using (StreamReader rdr = new StreamReader(@"c:\\file.txt"))
            {
                string line;
                while ((line = rdr.ReadLine()) != null)
                {
                    if (Regex.IsMatch(line, id, RegexOptions.IgnoreCase))
                    {
                        return line;
                    }
                }
            }
            return string.Empty;
        }

---

Best Regards, C.Gnanadurai ----------------------- Please mark the post as answer if it is helpfull to you

Answer 4

Firstly you start by splitting the string values retrieved from the text file into a string array (this assume you have already done).

            foreach (string strLine in lines)<br/> 

The above foreach loop, iterates through the string array, for for every string value it encounters it does the containing logic (the part inside the {}).

string[] csv = strLine.Split(',');

The above, splits the string line value, on the character ','.  So in essences you have a array of all the values in the string line. i.e. one string with the value 00000, one with 80 and so on.

<pre lang="x-c#">ArrayList values = new ArrayList();foreach (string value in csv)
                {
                    values.Add(value);
                }

The values array is then used to hold each of the string values.  The reason I have put them into a arraylist instead of leaving them in the string array, is because a arraylist has better search facilities.

Now that you have all the values in a array list, you simply add this array to a hashmap, using the first value (id) in the arraylist as the key. 

If this strill don't make sense please feel free to ask more questions, I am not the best atr explaining things, sorry.

K

Answer 5

Fantastic, with some tweaking for my project I have been able to get both methods to work quite well.

Thank you both very muchly. :D

Answer 6

Hi,

use data table to store the data and column name to fetch the values.

DataTable datatable;

        private void AddFileDataToTable() 

        {

            string FILELINE;

            datatable = new DataTable("Data");

            datatable.Columns.Add("ID");

            // use below code if "ID" column is always a numeric value

            //datatable.Columns.Add("ID", Type.GetType("System.Int32")); 

            

            datatable.PrimaryKey = new DataColumn[] { datatable.Columns["ID"] };

            datatable.Columns.Add("Column_1");

            datatable.Columns.Add("Column_2");

            datatable.Columns.Add("Column_3");

            

            using (System.IO.StreamReader file =             

                new System.IO.StreamReader(@"C:\AddFileDataToTable.txt"))

            {

                while ((file.Peek() > -1))

                {

                    FILELINE = file.ReadLine().Trim();

                    if (FILELINE != string.Empty)

                        datatable.Rows.Add(FILELINE.Split(new char[] { ',' }));

                }

            }

            DataRow datarow_array = datatable.Rows.Find("0001");

            // use below code if "ID" column is always a numeric value

            //DataRow datarow_array = datatable.Rows.Find(1); 

            if (datarow_array != null)

                MessageBox.Show(datarow_array["Column_1"].ToString());

        }