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Writing List<String> contents to text file after deleting string

I'm trying to get the contents of a Text File, delete a line of string, and re-write back to the Text File, deleting the line of string. I'm using StreamReader to get the text, importing into a List, removing the string, then rewriting using StreamWriter. My problems arises somewhere around the removing or writing of the string. Instead of writing back the existing, non deleted contents to the text file, all the text is replaced with :
System.Collections.Generic.List`1[System.String]
My code for this function is as follows:
{
for (int i = deleteDevice.Count - 1; i >= 0; i--)
{
string split = "";
//deleteDevice[i].Split(',').ToString();
List<string> parts = split.Split(',').ToList();
if (parts.Contains(deviceList.SelectedItem.ToString()))
{
deleteDevice.Remove(i.ToString());
}
}
if (deleteDevice.Count != 0) //Error Handling
{
writer.WriteLine(deleteDevice);
}
}
deviceList.Items.Remove(deviceList.SelectedItem);
}
I would just like the script to write back any string that isn't deleted (If there is any), without replacing it. Any help is appreciated, Cheers

You can read all the info from the text file into a list and then remove from the list and rewrite that to the text file.
I would change the list 'deleteDevice' to store a string array instead and use the code below to determine which item to remove.
List<int> toRemove = new List<int>();
int i = 0;
/*build a list of indexes to remove*/
foreach (string[] x in deleteDevice)
{
if (x[0].Contains(deviceList.SelectedItem.ToString()))
{
toRemove.Add(i);
}
i++;
}
/*Remove items from list*/
foreach (int fd in toRemove)
deleteDevice.RemoveAt(fd);
/*write to text file*/
using (StreamWriter writer = new StreamWriter("Devices.txt"))
{
if (deleteDevice.Count != 0) //Error Handling
{
foreach (string[] s in deleteDevice)
{
StringBuilder sb = new StringBuilder();
for (int fds = 0; fds < s.Length; fds++ )
{
sb.Append(s[fds] + ",");
}
string line = sb.ToString();
writer.WriteLine(line.Substring(0, line.Length - 1));
}
}
}
This isn't the best solution but should work for your needs. There's probably a much easier way of doing this.

The problem is in the following line:
writer.WriteLine(deleteDevice);
You're writing deleteDevice (I assume this is of type List). List.ToString() returns the type name of the list, because this has no specific implementation. What you want is
foreach(String s in deleteDevice)
{
writer.WriteLine(s);
}

Problems
deleteDevice is of type List<string>, and because it also doesn't overload ToString(), the default behaviour of List<string>.ToString() is to return the name of the type.
Hence your line writer.WriteLine(deleteDevice); writes the string System.Collections.Generic.List1[System.String]`.
Other than that, there are many things wrong with your code...
For example, you do this:
string split = "";
and then on the line afterwards you do this:
List<string> parts = split.Split(',').ToList();
But because split is "", this will always return an empty list.
Solution
To simplify the code, you could first write a helper method that will remove from a file all the lines that match a specified predicate:
public void RemoveUnwantedLines(string filename, Predicate<string> unwanted)
{
var lines = File.ReadAllLines(filename);
File.WriteAllLines(filename, lines.Where(line => !unwanted(line)));
}
Then you can write the predicate something like this (this might not be quite right; I don't really know exactly what your code is doing because it's not compilable and omits some of the types):
string filename = "My Filename";
string deviceToRemove= deviceList.SelectedItem.ToString();
Predicate<string> unwanted = line =>
line.Split(new [] {','})
.Contains(deviceToRemove);
RemoveUnwantedLines(filename, unwanted);

Reading a text file and inserting information into a new object

So I have a text file with information in the following format, with the name, email, and phone number.
Bill Molan, Bill.Molan#gmail.com, 612-789-7538
Greg Hanson, Greg.Hanson#gmail.com, 651-368-4558
Zoe Hall, Zoe.Hall#gmail.com, 952-778-4322
Henry Sinn, Henry.Sinn#gmail.com, 651-788-9634
Brittany Hudson, Brittany.Hudson#gmail.com, 612-756-4486
When my program starts, I want to read this file and make each row into a new Person(), which I will eventually add to a list. I am wanting to read each line, and then use the comma to separate each string to put into the constructor of Person(), which is a basic class:
public PersonEntry(string n, string e, string p)
{
Name = n;
Email = e;
Phone = p;
}
I have done some looking and I think that using a streamreader is going to work for reading the text file, but I'm not really sure where to go from here.

You can use the following method:
string line;
List listOfPersons=new List();
// Read the file and display it line by line.
System.IO.StreamReader file =
new System.IO.StreamReader(#"c:\yourFile.txt");
while((line = file.ReadLine()) != null)
{
string[] words = line.Split(',');
listOfPersons.Add(new Person(words[0],words[1],words[2]));
}
file.Close();

Assuming that the comma will never appear within the data:
Use StreamReader.ReadLine to read each line of text. With each line of text, use string.Split to split the line into an array of strings using the comma as the split character. Now you have an array of 3 strings where [0] is the name, [1] the email, and [2] the phone.

You can read all lines as below // assuming all lines will have 3 values always
var allLines = File.ReadAllLines(path);
var listOfPersons = new List<Person>();
foreach(var line in allLines)
{
var splittedLines = line.Split(new[] {","})
if(splittedLines!=null && splittedLines.Any())
{
listOfPersons.Add( new Person {
Name = splittedLines[0],
Email = splittedLines .Length > 1 ?splittedLines[1]:null,
Phone = splittedLines .Length > 2? splittedLines[2]:null,
});
}
}
this code is a sample must be checked for various conditions like array length etc also please check the

C# CSV file to array/list

I want to read 4-5 CSV files in some array in C#
I know that this question is been asked and I have gone through them...
But my use of CSVs is too much simpler for that...
I have csv fiels with columns of following data types....
string , string
These strings are without ',' so no tension...
That's it. And they aren't much big. Only about 20 records in each.
I just want to read them into array of C#....
Is there any very very simple and direct way to do that?

To read the file, use
TextReader reader = File.OpenText(filename);
To read a line:
string line = reader.ReadLine()
then
string[] tokens = line.Split(',');
to separate them.
By using a loop around the two last example lines, you could add each array of tokens into a list, if that's what you need.

This one includes the quotes & commas in fields. (assumes you're doing a line at a time)
using Microsoft.VisualBasic.FileIO; //For TextFieldParser
// blah blah blah
StringReader csv_reader = new StringReader(csv_line);
TextFieldParser csv_parser = new TextFieldParser(csv_reader);
csv_parser.SetDelimiters(",");
csv_parser.HasFieldsEnclosedInQuotes = true;
string[] csv_array = csv_parser.ReadFields();

Here is a simple way to get a CSV content to an array of strings. The CSV file can have double quotes, carriage return line feeds and the delimiter is a comma.
Here are the libraries that you need:
System.IO;
System.Collection.Generic;
System.IO is for FileStream and StreamReader class to access your file. Both classes implement the IDisposable interface, so you can use the using statements to close your streams. (example below)
System.Collection.Generic namespace is for collections, such as IList,List, and ArrayList, etc... In this example, we'll use the List class, because Lists are better than Arrays in my honest opinion. However, before I return our outbound variable, i'll call the .ToArray() member method to return the array.
There are many ways to get content from your file, I personally prefer to use a while(condition) loop to iterate over the contents. In the condition clause, use !lReader.EndOfStream. While not end of stream, continue iterating over the file.
public string[] GetCsvContent(string iFileName)
{
List<string> oCsvContent = new List<string>();
using (FileStream lFileStream =
new FileStream(iFilename, FileMode.Open, FileAccess.Read))
{
StringBuilder lFileContent = new StringBuilder();
using (StreamReader lReader = new StreamReader(lFileStream))
{
// flag if a double quote is found
bool lContainsDoubleQuotes = false;
// a string for the csv value
string lCsvValue = "";
// loop through the file until you read the end
while (!lReader.EndOfStream)
{
// stores each line in a variable
string lCsvLine = lReader.ReadLine();
// for each character in the line...
foreach (char lLetter in lCsvLine)
{
// check if the character is a double quote
if (lLetter == '"')
{
if (!lContainsDoubleQuotes)
{
lContainsDoubleQuotes = true;
}
else
{
lContainsDoubleQuotes = false;
}
}
// if we come across a comma
// AND it's not within a double quote..
if (lLetter == ',' && !lContainsDoubleQuotes)
{
// add our string to the array
oCsvContent.Add(lCsvValue);
// null out our string
lCsvValue = "";
}
else
{
// add the character to our string
lCsvValue += lLetter;
}
}
}
}
}
return oCsvContent.ToArray();
}
Hope this helps! Very easy and very quick.
Cheers!

Searching for text in a .txt

What would be the best way to search a text file that looks like this..?
efee|| Nbr| Address| Name |Phone|City|State|Zip abc
||455|gsgd |first last|gsg |fef |jk |0393 gjgj||jfj|ddg
|first last|fht |ree |hn |th ...more lines...
I started by reading in the file and all its contexts with a streamreader
I was thinking to count the "|" and grab the text between the 5th and 6th using substring but i'm not sure how to do the count of the "|". Or if someone has a better idea I'm open to it.
Tried something like this:
StreamReader file = new StreamReader(#"...");
string line;
int num=0;
while ((line = file.ReadLine()) != null)
{
for (int i = 1; i <= 6; i++)
{
if (line.Contains("|"))
{
num++;
}
}
int start = line.IndexOf("|");
int end = line.IndexOf("|");
string result = line.Substring(start, end - start - 1);
}
The text I want I beleive is always between the 5th and 6th "|"

You can do it like this:
var res = File
.ReadLines(#"FileName.txt")
.Select(line => line.Split(new[]{'|'}, StringSplitOptions.None)[5])
.ToList();
This produces a List<strings> from the file, where each string is the part of the corresponding line of the file taken from between the fifth and the sixth '|' separator.

For a delimited file you should use a parser - there is one in the Microsoft.VisualBasic.FileIO namespace - the TextFieldParser class, though you could also look at third-party libraries like the popular FileHelpers.
A simpler approach would be to use string.Split on the | character and getting the value in the corresponding index of the returned string[], however, if any of the fields are escaped and can validly contain | internally, this will fail.

You could split each line into an array:
while ((line = file.ReadLine()) != null)
{
var values = line.Split('|');
}

This should work
string txt = File.ReadAllText("file.txt");
string res = Regex.Match(txt, "\\|*?{5}(.+?)\\|", RegexOptions.Singleline).Result("$1");

C# read txt file and store the data in formatted array

I have a text file which contains following
Name address phone salary
Jack Boston 923-433-666 10000
all the fields are delimited by the spaces.
I am trying to write a C# program, this program should read a this text file and then store it in the formatted array.
My Array is as follows:
address
salary
When ever I am trying to look in google I get is how to read and write a text file in C#.
Thank you very much for your time.

You can use File.ReadAllLines method to load the file into an array. You can then use a for loop to loop through the lines, and the string type's Split method to separate each line into another array, and store the values in your formatted array.
Something like:
static void Main(string[] args)
{
var lines = File.ReadAllLines("filename.txt");
for (int i = 0; i < lines.Length; i++)
{
var fields = lines[i].Split(' ');
}
}

Do not reinvent the wheel. Can use for example fast csv reader where you can specify a delimeter you need.
There are plenty others on internet like that, just search and pick that one which fits your needs.

This answer assumes you don't know how much whitespace is between each string in a given line.
// Method to split a line into a string array separated by whitespace
private string[] Splitter(string input)
{
return Regex.Split(intput, #"\W+");
}
// Another code snippet to read the file and break the lines into arrays
// of strings and store the arrays in a list.
List<String[]> arrayList = new List<String[]>();
using (FileStream fStream = File.OpenRead(#"C:\SomeDirectory\SomeFile.txt"))
{
using(TextReader reader = new StreamReader(fStream))
{
string line = "";
while(!String.IsNullOrEmpty(line = reader.ReadLine()))
{
arrayList.Add(Splitter(line));
}
}
}