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How do i display the name base on the value of the text file with C#?

I have a text file containing the following data:
Jason,155
Peter,200
May,320
Jack,100
The above Texts are all in the same txt file.
I need to insert the name and the value of the person with the highest value into a separate textbox. I can't figure out how to read the highest value using StreamReader.
EDIT: This is the code that i used to read the txt file. But I'm not sure how to write the codes to pick the person with the highest value to display in a TextBox.
string[] Contestants = File.ReadAllLines(filePath);
foreach (var member in Contestants)
{
string[] first = member.Split(',');
string firstTemp = first[0] + "," + first[1];
}

This way is reading each line and filter it using Linq
var maxRow = File.ReadLines("file.txt")
.Where(line => !string.IsNullOrEmpty(line))
.Select(line => line.Split(','))
.Where(words => words.Length == 2)
.Aggregate((i1, i2) => int.Parse(i1[1]) >= int.Parse(i2[1]) ? i1 : i2);
string name = maxRow[0];
int number = int.Parse(maxRow[1]);

would it help, read line by line with streamreader, split by "," and parse the integer from string?
Read like this
using var fs = new FileStream(path, FileMode.Open, FileAccess.Read);
using var sr = new StreamReader(fs, Encoding.UTF8);
string line = String.Empty;
while ((line = sr.ReadLine()) != null) { Console.WriteLine(line); }
Best Regards

extracting a substring within a multiline string

I have a text file containing the following lines:
<TestInfo."Content">
{
<Label> "Content"
<Visible> "true"
"This is the text I want to get"
}
<TestInfo."Content2">
{
<Label> "Content2"
<Visible> "true"
"I don't want e.g. this"
}
I want to extract This is the text I want to get.
I tried e.g. the following:
string tmp = File.ReadAllText(textfile);
string result = Regex.Match(tmp, #"<Label> ""Content"" \n\s+ <Visible> ""true"" \n\s+ ""(.+?)""", RegexOptions.Singleline).Groups[1].Value;
However, in this case I get only the first word.
So, my output is: This
And I have no idea why...
I would appreciate any help. Thanks!

If you want the entire line after the line that starts with <Visible>, you'd better read the file line by line instead of using File.ReadAllText and a regular expression:
string result;
using (StreamReader sr = new StreamReader(textfile))
{
while (sr.Peek() >= 0)
{
string line = sr.ReadLine();
if (line.StartsWith("<Visible>"))
{
result = sr.ReadLine();
break;
}
}
}

Try this:
var tmp = File.ReadAllText("TextFile1.txt");
var result = Regex.Match(tmp, "This is the text I want to get", RegexOptions.Multiline);
if (result.Groups.Count> 0)
for (int i = 0; i < result.Groups.Count; i++)
Console.WriteLine(result.Groups[i].Value);
else
Console.WriteLine("string not found.");
Regards,
//jafc

You could change your regex this way:
var result = Regex.Match(tmp, #"<Visible> ""true""\s*""([\S ]+)""", RegexOptions.Singleline).Groups[1].Value;
If you want to get all the matches, not only the first one, you could use Regex.Matches

Thanks a lot for your input! This helped me to find a final solution:
First, I extracted only a small part containing the string I want to extract to avoid ambiguities:
string[] tmp = File.ReadAllLines(textfile);
List<string> Content = new List<string>();
bool dumpA = false;
Regex regBEGIN = new Regex(#"<TestInfo\.""Content"">");
Regex regEND = new Regex(#"<TestInfo\.""Content2"">");
foreach (string line in tmp)
{
if (dumpA)
Content.Add(line.Trim());
if (regBEGIN.IsMatch(line))
dumpA = true;
if (regEND.IsMatch(line)) break;
}
Then I can extract the (now only once existing) line starting with '"':
string result = "";
foreach (string line in Content)
{
if (line.StartsWith("\""))
{
result = line;
result = result.Replace("\"", "");
result = result.Trim();
}
}

Effective way of reading text file in c# for line to line operation

I'm having problem in reading text file for line to line addition operation. I have used following syntax
StreamReader reader = new StreamReader("input.txt");
string line;
while ((line = reader.ReadLine()) != null)
string[] splitted = line.Split('#');
string first = splitted[0].Trim();
string second = splitted[1].Trim();
I have used this syntax to separate the input from text file if file has following values.
12#15
15#7
13#14
23#31
x= Convert.ToInt32(first);
y= Convert.ToInt32(second);
sum = x+y;
txtBox.text = Convert.ToString(sum);
the problem is it only executes the last line. It only calculate the sum of 23 and 31 and show only but I want to add 12 and 15 first and show it in textbox similarly I want to add others. please help me in forming appropriate syntax.

The question is vague one, however, I suggest using Linq:
var source = File
.ReadLines("input.txt") // read line by line
.Select(line => line.Split('#')) // split each line
//.Where(items => items.Length == 2) // you may want to filter out the lines
.Select(items => new { // convert each line into anonymous class
first = items[0].Trim(),
second = items[1].Trim()
});
You can add as many Select (line to line opetations) as you want. Then you can proceed the items in a foreach loop:
foreach (var item in source) {
...
// Let's read some fields from the anonymous object
var first = item.first;
var second = item.second;
...
}
Edit: according to the edited question you want just to sum up which can be done via Linq as well:
var result = File
.ReadLines("input.txt")
.Select(line => line.Split('#'))
//.Where(items => items.Length == 2) // you may want to filter out the lines
.Sum(items => int.Parse(items[0]) + int.Parse(items[1]));
txtBox.text = result.ToString();

It doesn't only read the last line, you just never do anything with the other iterations. Currently you just keep reassigning line with the value of the latest line that has been read, I presume you hope to save these to a list or similar
StreamReader reader = new StreamReader("input.txt");
string line;
List<string> allLines = new List<string>();
while ((line = reader.ReadLine()) != null)
allLines.Add(line);

here you can test your File and Load The data into a DataTable this should be pretty straight forward.
DataTable dtTextFileData = new DataTable();
dtTextFileData.Columns.AddRange(new []
{
new DataColumn("First", typeof(string)),
new DataColumn("Second", typeof(string))
});
StreamReader file = new StreamReader(#"c:\YourFilePath\input.txt");
string line = file.ReadLine();
while (line != null)
{
string[] fields = line.Split('#');
DataRow dr = dtTextFileData.NewRow();
dr["First"] = fields[0].ToString();
dr["Second"] = fields[1].ToString();
dtTextFileData.Rows.Add(dr);
line = file.ReadLine();
}

Copying CSV file while reordering/adding empty columns

Copying CSV file while reordering/adding empty columns.
For example if ever line of incoming file has values for 3 out of 10 columns in order different from output like (except first which is header with column names):
col2,col6,col4 // first line - column names
2, 5, 8 // subsequent lines - values for 3 columns
and output expected to have
col0,col1,col2,col3,col4,col5,col6,col7,col8,col9
then output should be "" for col0,col1,col3,col5,col7,col8,col9,and values from col2,col4,col4 in the input file. So for the shown second line (2,5,8) expected output is ",,2,,5,,8,,,,,"
Below code I've tried and it is slower than I want.
I have two lists.
The first list filecolumnnames is created by splitting a delimited string (line) and this list gets recreated for every line in the file.
The second list list has the order in which the first list needs to be rearranged and re concatenated.
This works
string fileName = "F:\\temp.csv";
//file data has first row col3,col2,col1,col0;
//second row: 4,3,2,1
//so on
string fileName_recreated = "F:\\temp_1.csv";
int count = 0;
const Int32 BufferSize = 1028;
using (var fileStream = File.OpenRead(fileName))
using (var streamReader = new StreamReader(fileStream, Encoding.UTF8, true, BufferSize))
{
String line;
List<int> list = new List<int>();
string orderedcolumns = "\"\"";
string tableheader = "col0,col1,col2,col3,col4,col5,col6,col7,col8,col9,col10";
List<string> tablecolumnnames = new List<string>();
List<string> filecolumnnames = new List<string>();
while ((line = streamReader.ReadLine()) != null)
{
count = count + 1;
StringBuilder sb = new StringBuilder("");
tablecolumnnames = tableheader.Split(',').ToList();
if (count == 1)
{
string fileheader = line;
//fileheader=""col2,col1,col0"
filecolumnnames = fileheader.Split(',').ToList();
foreach (string col in tablecolumnnames)
{
int index = filecolumnnames.IndexOf(col);
if (index == -1)
{
sb.Append(",");
// orderedcolumns=orderedcolumns+"+\",\"";
list.Add(-1);
}
else
{
sb.Append(filecolumnnames[index] + ",");
//orderedcolumns = orderedcolumns+ "+filecolumnnames["+index+"]" + "+\",\"";
list.Add(index);
}
// MessageBox.Show(orderedcolumns);
}
}
else
{
filecolumnnames = line.Split(',').ToList();
foreach (int items in list)
{
//MessageBox.Show(items.ToString());
if (items == -1)
{
sb.Append(",");
}
else
{
sb.Append(filecolumnnames[items] + ",");
}
}
//expected format sb.Append(filecolumnnames[3] + "," + filecolumnnames[2] + "," + filecolumnnames[2] + ",");
//sb.Append(orderedcolumns);
var result = String.Join (", ", list.Select(index => filecolumnnames[index]));
}
using (FileStream fs = new FileStream(fileName_recreated, FileMode.Append, FileAccess.Write))
using (StreamWriter sw = new StreamWriter(fs))
{
sw.WriteLine(sb.ToString());
}
}
I am trying to make it faster by constructing a string orderedcolumns and remove the second for each loop which happens for every row and replace it with constructed string.
so if you uncomment the orderedcolumns string construction orderedcolumns = orderedcolumns+ "+filecolumnnames["+index+"]" + "+\",\""; and uncomment the append sb.Append(orderedcolumns); I am expecting the value inside the constructed string but when I append the orderedcolumns it is appending the text i.e.
""+","+filecolumnnames[3]+","+filecolumnnames[2]+","+filecolumnnames[1]+","+filecolumnnames[0]+","+","+","+","+","+","+","
i.e. I instead want it to take the value inside the filecolumnnames[3] list and not the filecolumnnames[3] name itself.
Expected value: if that line has 1,2,3,4
I want the output to be 4,3,2,1 as filecolumnnames[3] will have 4, filecolumnnames[2] will have 3..

String.Join is the way to construct comma/space delimited strings from sequence.
var result = String.Join (", ", list.Select(index => filecolumnnames[index]);
Since you are reading only subset of columns and orders in input and output don't match I'd use dictionary to hold each row of input.
var row = tablecolumnnames
.Zip(line.Split(','), (Name,Value)=> new {Name,Value})
.ToDictionary(x => x.Name, x.Value);
For output I'd fill sequence from defaults or input row:
var outputLine = String.Join(",",
filecolumnnames
.Select(name => row.ContainsKey(name) ? row[name] : ""));
Note code is typed in and not compiled.

orderedcolumns = orderedcolumns+ "+filecolumnnames["+index+"]" + "+\",\""; "
should be
orderedcolumns = orderedcolumns+ filecolumnnames[index] + ",";
you should however use join as others have pointed out. Or
orderedcolumns.AppendFormat("{0},", filecolumnnames[index]);
you will have to deal with the extra ',' on the end

C# Why do I only get partial results when parsing out a CSV or TSV file?

I am trying to get the second value from a CSV file with 100 rows. I am getting the first 42 values then it stops... no error messege, or error handling at all for that matter. I am perplexed and am on a timeline. It is also doing it for a TSV file, but giving the first 43 results. Please help and let me know if it looks strange to you.
I am using streamreader, reading each line into a string array, splitting the array and taking the second value and adding it to a list...
string path = #"C:\Users\dave\Desktop\codes\testfile.txt";
StreamReader sr = new StreamReader(path);
List<string> stkno = new List<string>();
foreach (var line in path)
{
string s = sr.ReadLine();
string[] words = s.Split(',');
stkno.Add(words[1]);
}
var message = string.Join(",", stkno.ToArray());
MessageBox.Show(message);

Your path variable is a string. That means when you foreach over it, you're getting a sequence of characters - 'C' then ':' then '\' etc. I don't think that's what you mean to do...
Here's a simpler approach using File.ReadLines:
string path = #"C:\Users\dave\Desktop\codes\testfile.txt";
List<string> stkno = (from line in File.ReadLines(path)
let words = line.Split(',')
select words[1]).ToList();
Or:
string path = #"C:\Users\dave\Desktop\codes\testfile.txt";
List<string> stkno = File.ReadLines(path)
.Select(line => line.Split(',')[1])
.ToList();
If you're using .NET 3.5 and you don't mind reading the whole file in one go, you can use File.ReadAllLines instead.

You are accidentally iterating over the number of characters in the file path instead of the number of lines in the string. This change should fix that:
string path = #"C:\Users\dave\Desktop\codes\testfile.txt";
StreamReader sr = new StreamReader(path);
List<string> stkno = new List<string>();
while (sr.Peek() >= 0)
{
string s = sr.ReadLine();
string[] words = s.Split(',');
stkno.Add(words[1]);
}
var message = string.Join(",", stkno.ToArray());
MessageBox.Show(message);

How about this:
string path = #"C:\Users\dave\Desktop\codes\testfile.txt";
var secondWords = from line in File.ReadAllLines(path)
let words = line.Split(',')
select words[1];
var message = string.Join(",", secondWords.ToArray());

I think you mean to do:
string path = #"C:\Users\dave\Desktop\codes\testfile.txt";
StreamReader sr = new StreamReader(path);
List<string> stkno = new List<string>();
string s;
while(s = sr.ReadLine() != null)
{
string[] words = s.Split(',');
stkno.Add(words[1]);
}
var message = string.Join(",", stkno.ToArray());
MessageBox.Show(message);