Develop Reference

C# Adding CSV to a list

I try to add the containing of a csv file to a new list. It's a list of different types of people with caracteristics like the function, a matricule, the last name, the firstname and a sex. So I managed to read the file but I don't really know how to process to add the containing of the file to my list.Here is my code :
`private static void ReadTest()
{
int count = 0;
string line;
Char c = ';';
StreamReader file= new StreamReader("Listing.csv");
while ((line= file.ReadLine()) != null)
{
String[] substrings = line.Split(c);
foreach (var substring in substrings)
{
Console.WriteLine(substring);
}
count++;
}
fichier.Close();
System.Console.WriteLine("Number of lines : {0}.", count);
}
static void Main(string[] args)
{
List<Personnel> Workers = new List<Personnel>();
}
'

Why don't you use CSVHelper, it will be as simple as the following:
var csv = new CsvReader( textReader );
var records = csv.GetRecords<Personnel>();
//then loop through
foreach( var record in records )
{
}
you just need to install the nuget package:
Install-Package CsvHelper
Check this for more information.

Replace the foreach loop with something like the following:
var person = new Personnel();
person.firstname = substrings[0];
person.lastname = substrings[1];
person.function = substrings[2];
//continue until all variables assigned.
Workers.Add(person);
Also, if the Workers list is not a static list, then make ReadTest return a List and create a list within the function.
Like this:
private static List<Personnel> ReadTest()
{
int count = 0;
string line;
Char c = ';';
StreamReader file= new StreamReader("Listing.csv");
var Workers = new List<Personnel>();
while ((line= file.ReadLine()) != null)
{
String[] substrings = line.Split(c);
var person = new Personnel();
person.firstname = substrings[0];
person.lastname = substrings[1];
person.function = substrings[2];
//continue until all variables assigned.
Workers.Add(person);
count++;
}
file.Close();
System.Console.WriteLine("Number of lines : {0}.", count);
return Workers;
}
static void Main(string[] args)
{
List<Personnel> Workers = ReadTest();
}

Import two CSV, add specific columns from one CSV and import changes to new CSV (C#)

i have to import 2 CSV's.
CSV 1 [49]: Including about 50 tab seperated colums.
CSV 2:[2] Inlcudes 3 Columns which should be replaced on the [3] [6] and [11] place of my first csv.
So heres what i do:
1) Importing the csv and split into a array.
string employeedatabase = "MYPATH";
List<String> status = new List<String>();
StreamReader file2 = new System.IO.StreamReader(filename);
string line = file2.ReadLine();
while ((line = file2.ReadLine()) != null)
{
string[] ud = line.Split('\t');
status.Add(ud[0]);
}
String[] ud_status = status.ToArray();
PROBLEM 1: i have about 50 colums to handle, ud_status is just the first, so do i need 50 Lists and 50 String arrays?
2) Importing the second csv and split into a array.
List<String> vorname = new List<String>();
List<String> nachname = new List<String>();
List<String> username = new List<String>();
StreamReader file = new System.IO.StreamReader(employeedatabase);
string line3 = file.ReadLine();
while ((line3 = file.ReadLine()) != null)
{
string[] data = line3.Split(';');
vorname.Add(data[0]);
nachname.Add(data[1]);
username.Add(data[2]);
}
String[] db_vorname = vorname.ToArray();
String[] db_nachname = nachname.ToArray();
String[] db_username = username.ToArray();
PROBLEM 2: After loading these two csv's i dont know how to combine them, and change to columns as mentioned above ..
somethine like this?
mynewArray = ud_status + "/t" + ud_xy[..n] + "/t" + changed_colum + ud_xy[..n];
save "mynewarray" into tablulator seperated csv with encoding "utf-8".

To read the file into a meaningful format, you should set up a class that defines the format of your CSV:
public class CsvRow
{
public string vorname { get; set; }
public string nachname { get; set; }
public string username { get; set; }
public CsvRow (string[] data)
{
vorname = data[0];
nachname = data[1];
username = data[2];
}
}
Then populate a list of this:
List<CsvRow> rows = new List<CsvRow>();
StreamReader file = new System.IO.StreamReader(employeedatabase);
string line3 = file.ReadLine();
while ((line3 = file.ReadLine()) != null)
{
rows.Add(new CsvRow(line3.Split(';'));
}
Similarly format your other CSV and include unused properties for the new fields. Once you have loaded both, you can populate the new properties from this list in a loop, matching the records by whatever common field the CSVs hopefully share. Then finally output the resulting data to a new CSV file.

Your solution is not to use string arrays to do this. That will just drive you crazy. It's better to use the System.Data.DataTable object.
I didn't get a chance to test the LINQ lambda expression at the end of this (or really any of it, I wrote this on a break), but it should get you on the right track.
using (var ds = new System.Data.DataSet("My Data"))
{
ds.Tables.Add("File0");
ds.Tables.Add("File1");
string[] line;
using (var reader = new System.IO.StreamReader("FirstFile"))
{
//first we get columns for table 0
foreach (string s in reader.ReadLine().Split('\t'))
ds.Tables["File0"].Columns.Add(s);
while ((line = reader.ReadLine().Split('\t')) != null)
{
//and now the rest of the data.
var r = ds.Tables["File0"].NewRow();
for (int i = 0; i <= line.Length; i++)
{
r[i] = line[i];
}
ds.Tables["File0"].Rows.Add(r);
}
}
//we could probably do these in a loop or a second method,
//but you may want subtle differences, so for now we just do it the same way
//for file1
using (var reader2 = new System.IO.StreamReader("SecondFile"))
{
foreach (string s in reader2.ReadLine().Split('\t'))
ds.Tables["File1"].Columns.Add(s);
while ((line = reader2.ReadLine().Split('\t')) != null)
{
//and now the rest of the data.
var r = ds.Tables["File1"].NewRow();
for (int i = 0; i <= line.Length; i++)
{
r[i] = line[i];
}
ds.Tables["File1"].Rows.Add(r);
}
}
//you now have these in functioning datatables. Because we named columns,
//you can call them by name specifically, or by index, to replace in the first datatable.
string[] columnsToReplace = new string[] { "firstColumnName", "SecondColumnName", "ThirdColumnName" };
for(int i = 0; i < ds.Tables[0].Rows.Count; i++)
{
//you didn't give a sign of any relation between the two tables
//so this is just by row, and assumes the row count is equivalent.
//This is also not advised.
//if there is a key these sets of data share
//you should join on them instead.
foreach(DataRow dr in ds.Tables[0].Rows[i].ItemArray)
{
dr[3] = ds.Tables[1].Rows[i][columnsToReplace[0]];
dr[6] = ds.Tables[1].Rows[i][columnsToReplace[1]];
dr[11] = ds.Tables[1].Rows[i][columnsToReplace[2]];
}
}
//ds.Tables[0] now has the output you want.
string output = String.Empty;
foreach (var s in ds.Tables[0].Columns)
output = String.Concat(output, s ,"\t");
output = String.Concat(output, Environment.NewLine); // columns ready, now the rows.
foreach (DataRow r in ds.Tables[0].Rows)
output = string.Concat(output, r.ItemArray.SelectMany(t => (t.ToString() + "\t")), Environment.NewLine);
if(System.IO.File.Exists("MYPATH"))
using (System.IO.StreamWriter file = new System.IO.StreamWriter("MYPATH")) //or a variable instead of string literal
{
file.Write(output);
}
}

With Cinchoo ETL - an open source file helper library, you can do the merge of CSV files as below. Assumed the 2 CSV file contains same number of lines.
string CSV1 = #"Id Name City
1 Tom New York
2 Mark FairFax";
string CSV2 = #"Id City
1 Las Vegas
2 Dallas";
dynamic rec1 = null;
dynamic rec2 = null;
StringBuilder csv3 = new StringBuilder();
using (var csvOut = new ChoCSVWriter(new StringWriter(csv3))
.WithFirstLineHeader()
.WithDelimiter("\t")
)
{
using (var csv1 = new ChoCSVReader(new StringReader(CSV1))
.WithFirstLineHeader()
.WithDelimiter("\t")
)
{
using (var csv2 = new ChoCSVReader(new StringReader(CSV2))
.WithFirstLineHeader()
.WithDelimiter("\t")
)
{
while ((rec1 = csv1.Read()) != null && (rec2 = csv2.Read()) != null)
{
rec1.City = rec2.City;
csvOut.Write(rec1);
}
}
}
}
Console.WriteLine(csv3.ToString());
Hope it helps.
Disclaimer: I'm the author of this library.

C# CSV to JSON per row

Major Edit: I am doing a bad job of explaining :(
I have two classes:
public class UserDefinitions// a list of 'Items', each'group of items belong to a user. I handle User logic elsewhere, and it works flawlessly.
{
public List<Item> items { get; set; }
}
public class Item //the User definitions. A user could have 1 or 15 of these. They would all be a single 'line' from the CSV file.
{
public string definitionKey { get; set; }
public string defName { get; set; }
public string defValue { get; set; }
}
Which I wanna build with a CSV File. I build this CSV File, so I make it using the same parameters every time.
I run SQL on my company's DB to generate results like so: http://i.imgur.com/gS1UJot.png
Then I read the file like so:
class Program
{
static void Main(string[] args)
{
var userData = new UserDefinitions();
var csvList = new List<Item>();
string json = "";
string fPath = #"C:\test\csvTest.csv";
var lines = File.ReadAllLines(fPath);
Console.WriteLine(lines);
List<string> udata = new List<string>(lines);
foreach (var line in udata)
{
string[] userDataComplete = line.Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries);// this cleans any empty cells from the CSV
csvList.Add(new Item { definitionKey = userDataComplete[1], defName = userDataComplete[2], defValue = userDataComplete[3] });
}
json = JsonConvert.SerializeObject(csvList); //everything below is for debugging/tracking progress
Console.WriteLine(json);
Console.ReadKey();
StreamWriter sw = new StreamWriter("C:\\test\\testjson.txt");
sw.WriteLine(json);
sw.Close();
}
}
This ALMOST does what I want. The output json is from the first 'column' of the csv data
[{"definitionKey":"uuid1","defName":"HairColor","defValue":"Brown"},{"definitionKey":"uuid1","defName":"HairColor","defValue":"Blonde"},{"definitionKey":"uuid1","defName":"HairColor","defValue":"Blue"}]
When using the screen shot as an example, the wanted output should be
[{"attributeDefinitionKey":"uuid1","name":"HairColor","value":"Brown"},{"definitionKey":"uuid2","defName":"FreckleAmount","defValue":"50"}]
[{"attributeDefinitionKey":"uuid1","name":"HairColor","value":"Blonde"},{"definitionKey":"uuid2","defName":"FreckleAmount","defValue":"null"}]
[{"attributeDefinitionKey":"uuid1","name":"HairColor","value":"Blue"},{"definitionKey":"uuid3","defName":"Tattoos","defValue":"5"}]
I can't pick out certain aspects at will, or apply them to Items. For example there maybe 10 users or 5000 users, but the definitionKey will always be the [1], and adding '3' will get every subsequent defintionKey. Just like the defName will always be in the [2] spot and adding 3 will get every subsequent defName if there are any, this is all per line.
I know I have to add some +3 logic, but not quite sure how to incorporate that. Maybe a for loop? a nested for loop after a foreach loop? I feel I am missing something obvious!
Thanks again for any help

This reads the csv line for line and converts each row to json, while adapting to the change in the amount of columns.
This only works if the CSV follows your rules:
one userId and
x amount of "Things" with 3 columns per "Thing".
private static void Main(string[] args)
{
var file = new StreamReader(#"C:\test\csvTest.csv");
string line;
var itemsJson = new List<string>();
file.ReadLine();
while ((line = file.ReadLine()) != null)
{
var sb = new StringBuilder();
var fields = line.Split(',');
sb.Append(GetKeyValueJson("UserId", fields[0]));
for (var i = 1; i < fields.Length; i += 3)
{
var x = (i + 3) / 3;
sb.Append(GetKeyValueJson($"Thing {i + x} ID", fields[i]));
sb.Append(GetKeyValueJson($"Thing {i + x} ID", fields[i + 1]));
sb.Append(i + 3 == fields.Length
? GetKeyValueJson($"Thing {i + x} ID", fields[i + 2], true)
: GetKeyValueJson($"Thing {i + x} ID", fields[i + 2]));
}
itemsJson.Add(WrapJson(sb.ToString()));
}
var json = WrapItems(itemsJson);
Console.ReadLine();
}
private static string GetKeyValueJson(string id, string value, bool lastPair = false)
{
var sb = new StringBuilder();
sb.Append('"');
sb.Append(id);
sb.Append('"');
sb.Append(':');
sb.Append('"');
sb.Append(value);
sb.Append('"');
if (!lastPair)
sb.Append(',');
return sb.ToString();
}
private static string WrapJson(string s)
{
var sb = new StringBuilder();
sb.Append('{');
sb.Append(s);
sb.Append('}');
return sb.ToString();
}
private static string WrapItems(List<string> jsonList)
{
var sb = new StringBuilder();
sb.Append('"');
sb.Append("Items");
sb.Append('"');
sb.Append(':');
sb.Append('[');
sb.Append(jsonList.Aggregate((current, next) => current + "," + next));
sb.Append(']');
return WrapJson(sb.ToString());
}
}
It's not pretty and sorting would be tough, but it should adapt to the column amount as long as it is in 3's.

Multiple List return using Tuple class in C#

I have a class Helper with 2 methods
public static List<string> GetCountryName()
{
List<string> CountryName = new List<string>();
using (var sr = new StreamReader(#"Country.txt"))
{
string line;
while ((line = sr.ReadLine()) != null)
{
int index = line.LastIndexOf(" ");
CountryName.Add(line.Substring(0, index));
}
}
return CountryName;
}
public static List<string> GetCountryCode()
{
List<string> CountryCode = new List<string>();
using (var sr = new StreamReader(#"Country.txt"))
{
string line;
while ((line = sr.ReadLine()) != null)
{
int index = line.LastIndexOf(" ");
CountryCode.Add(line.Substring(index + 1));
}
}
return CountryCode;
}
I bind these return values with my WPF ComboBox as follows
ddlCountryName.ItemsSource = Helper.GetCountryName();
ddlCountryCode.ItemsSource = Helper.GetCountryCode();
I wanted to return these List in a single method and went through these links
Tuple Class
https://stackoverflow.com/a/10278769
After going through it I tries like this but could not able to make it properly from line no-3 Tuple<List<string>> CountryName = new Tuple<List<string>>
public static Tuple<List<string>,List<string>> GetAllData()
{
Tuple<List<string>> CountryName = new Tuple<List<string>>
List<string> CountryCode = new List<string>();
using (var sr = new StreamReader(#"Country.txt"))
{
string line;
while ((line = sr.ReadLine()) != null)
{
int index = line.LastIndexOf(" ");
CountryName.Add(line.Substring(0, index));
CountryCode.Add(line.Substring(index + 1));
}
}
return CountryName;
return CountryCode;
}
Please help me to return List item wise and bind in the ItemsSource as per the below code
ddlCountryName.ItemsSource = Helper.GetCountryName();

try this (not tested)
public static Tuple<List<string>, List<string>> GetAllData()
{
List<string> CountryName = new List<string>();
List<string> CountryCode = new List<string>();
using (var sr = new StreamReader(#"Country.txt"))
{
string line;
while ((line = sr.ReadLine()) != null)
{
int index = line.LastIndexOf(" ");
CountryName.Add(line.Substring(0, index));
CountryCode.Add(line.Substring(index + 1));
}
}
return new Tuple<List<string>, List<string>>(CountryName,CountryCode);
}

A Tuple is a pack of two or more values and the types of these values are specified through generic parameters when you create a Tuple object. You are creating a Tuple of a single value, which has no meanings. Try creating it like this:
Tuple<List<string>, List<string>> CountryName = new Tuple<List<string>, List<string>>();
Also note that a function cannot have more than one return statements. You should add both your lists to the Tuple object and then return it in one go.
Your final function will be something like (keep your two existing functions and create a new function that calls them):
public static Tuple<List<string>,List<string>> GetAllData()
{
return new Tuple<List<string>, List<string>>(GetCountryName(), GetCountryCode());
}
An alternate approach:
public static List<Tuple<string, string>> GetAllData()
{
List<Tuple<string, string>> Result = new List<Tuple<string, string>>();
using (var sr = new StreamReader(#"Country.txt"))
{
string line;
while ((line = sr.ReadLine()) != null)
{
int index = line.LastIndexOf(" ");
var Name = line.Substring(0, index);
var Code = line.Substring(index + 1);
Result.Add(new Tuple<string, string>(Name, Code));
}
}
return Result;
}
In the first case, you do your binding directly to the Tuple members:
ddlCountryName.ItemsSource = Result.Item1;
ddlCountryCode.ItemsSource = Result.Item2;
In the second case, you can do some further linq to get your individual lists from the returned object:
ddlCountryName.ItemsSource = Result.Select(x => x.Item1).ToArray();
ddlCountryCode.ItemsSource = Result.Select(x => x.Item2).ToArray();

Saving to a class variable

Hi i need to save the "pri1" variable to a class variable so other methods of the same class would be able to access.
in between these lines
"pri1.Remove(last);
foreach (string item in pri1)"
void downloader_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
{
if (e.Error == null)
{
Stream responseStream = e.Result;
StreamReader responseReader = new StreamReader(responseStream);
string response = responseReader.ReadToEnd();
string[] split1 = Regex.Split(response, "},{");
List<string> pri1 = new List<string>(split1);
pri1.RemoveAt(0);
string last = pri1[pri1.Count() - 1];
pri1.Remove(last);
foreach (string item in pri1)
{
string abc = "[{" + item + "}]";
byte[] buf = System.Text.Encoding.UTF8.GetBytes(abc);
MemoryStream ms = new MemoryStream(buf);
JsonArray users = (JsonArray)JsonArray.Load(ms);
var members = from member in users
//where member["SEARCHVAL"]
select member;
foreach (JsonObject member in members)
{
string schname = member["SEARCHVAL"];
string axisX = member["X"];
string axisY = member["Y"];
// Do something...
string jsonCoordinateString = "{'Coordinates':[{'X':" + axisX + ",'Y':" + axisY + "}]}";
CustomCoordinateList coordinateList = DeserializeJson<CustomCoordinateList>(jsonCoordinateString);
GraphicsLayer graphicsLayer = MyMap.Layers["MyGraphicsLayer_Primary"] as GraphicsLayer;
for (int i = 0; i < coordinateList.Coordinates.Count; i++)
{
Graphic graphic = new Graphic()
{
Geometry = new MapPoint(coordinateList.Coordinates[i].X, coordinateList.Coordinates[i].Y),
Symbol = i > 0 ? PrimarySchoolMarkerSymbol : PrimarySchoolMarkerSymbol
};
graphic.Attributes.Add("PrimarySchool", schname);
graphicsLayer.Graphics.Add(graphic);
}
}
}
}
}

You need to add a field to the class:
List<string> myField;
You can then use the field as a variable anywhere in the class.

Assuming there is a field in the class that can store the List<string> type
this.VariableName = pri1;
If there isn't a variable in the class and you haven't defined it your self you'll need to subclass and add it.