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How can I access multi-element List data stored in a public class?

My first question on SO:
I created this public class, so that I can store three elements in a list:
public class myMultiElementList
{
public string Role {get;set;}
public string Country {get;set;}
public int Commonality {get;set;}
}
In my main class, I then created a new list using this process:
var EmployeeRolesCountry = new List<myMultiElementList>();
var rc1 = new myMultiElementList();
rc1.Role = token.Trim();
rc1.Country = country.Trim();
rc1.Commonality = 1;
EmployeeRolesCountry.Add(rc1);
I've added data to EmployeeRolesCountry and have validated that has 472 lines. However, when I try to retrieve it as below, my ForEach loop only retrieves the final line added to the list, 472 times...
foreach (myMultiElementList tmpClass in EmployeeRolesCountry)
{
string d1Value = tmpClass.Role;
Console.WriteLine(d1Value);
string d2Value = tmpClass.Role;
Console.WriteLine(d2Value);
int d3Value = tmpClass.Commonality;
Console.WriteLine(d3Value);
}
This was the most promising of the potential solutions I found on here, so any pointers greatly appreciated.
EDIT: adding data to EmployeeRolesCountry
/*
Before this starts, data is taken in via a csvReader function and parsed
All of the process below is concerned with two fields in the csv
One is simply the Country. No processing necessary
The other is bio, and this itself needs to be parsed and cleansed several times to take roles out
To keep things making sense, I've taken much of the cleansing out
*/
private void File_upload_Click(object sender, EventArgs e)
{
int pos = 0;
var EmployeeRolesCountry = new List<myMultiElementList>();
var rc1 = new myMultiElementList();
int a = 0;
delimiter = ".";
string token;
foreach (var line in records.Take(100))
{
var fields = line.ToList();
string bio = fields[5];
string country = fields[4];
int role_count = Regex.Matches(bio, delimiter).Count;
a = bio.Length;
for (var i = 0; i < role_count; i++)
{
//here I take first role, by parsing on delimiter, then push back EmployeeRolesCountry with result
pos = bio.IndexOf('.');
if (pos != -1)
{
token = bio.Substring(0, pos);
string original_token = token;
rc1.Role = token.Trim();
rc1.Country = country.Trim();
rc1.Commonality = 1;
EmployeeRolesCountry.Add(rc1);
a = original_token.Length;
bio = bio.Remove(0, a + 1);
}
}
}
}

EDIT:
When grouped by multiple properties, this is how we iterate through the grouped items:
var employeesGroupedByRolwAndCountry = EmployeeRolesCountry.GroupBy(x => new { x.Role, x.Country });
employeesGroupedByRolwAndCountry.ToList().ForEach
(
(countryAndRole) =>
{
Console.WriteLine("Group {0}/{1}", countryAndRole.Key.Country, countryAndRole.Key.Role);
countryAndRole.ToList().ForEach
(
(multiElement) => Console.WriteLine(" : {0}", multiElement.Commonality)
);
}
);
__ ORIGINAL POST __
You are instantiating rc1 only once (outside the loop) and add the same instance to the list.
Please make sure that you do
var rc1 = new myMultiElementList();
inside the loop where you are adding the elements, and not outside.
All references are the same in your case:
var obj = new myObj();
for(i = 0; i < 5; i++)
{
obj.Prop1 = "Prop" + i;
list.Add(obj);
}
now the list has 5 elements, all pointing to the obj (the same instance, the same object in memory), and when you do
obj.Prop1 = "Prop" + 5
you update the same memory address, and all the pointers in the list points to the same instance so, you are not getting 472 copies of the LAST item, but getting the same instance 472 times.
The solution is simple. Create a new instance every time you add to your list:
for(i = 0; i < 5; i++)
{
var obj = new myObj();
obj.Prop1 = "Prop" + i;
list.Add(obj);
}
Hope this helps.

Can't convert systems.collections.generic.list<systems.collections.generic.list<string>> to string

Not sure why this isn't working, but I have:
public static string SetRows(DataTable table, int maximumCount)
{
var finalFile = new List<List<string>>();
foreach (DataRow row in table.Rows)
{
int i = 0;
List<string> excelTotal = new List<string>();
for (i = 0; i < maximumCount; i++)
{
excelTotal.Add(row[i].ToString());
}
finalFile.Add(excelTotal);
}
return finalFile;
}
I'm creating a list inside another list.

The return type of the method is string. It should be List<List<string>> as this is what the method is returning.
Change the method declaration to be:
public static List<List<string>> SetRows(DataTable table, int maximumCount)

Pass by reference issue using a delegate inside a loop

I have the following code which creates and returns a Dictionary<int, List<string>>
private static readonly Random rnd = new Random();
private static Dictionary<int, List<string>> GenerateValues(string entityType, int rows)
{
var values = new Dictionary<int, List<string>>();
var baseValues = new List<string> { "99 Hellesdon Road","Home","Norfolk","NR6 5EG","Norwich" };
Action<int> rowLoop = null;
switch (entityType)
{
case "Employer":
rowLoop = (row) =>
{
var employer = new List<string>
{
$"Employer {rnd.Next(10000, 99999)}",
$"{rnd.Next(100000000, 999999999)}",
"TRUE"
};
var rowValue = baseValues;
rowValue.AddRange(employer);
values.Add(row, rowValue);
};
break;
case "AssessmentCentre":
rowLoop = (row) =>
{
var rowValue = baseValues;
rowValue.Add($"Assessment Centre {rnd.Next(10000, 99999)}");
values.Add(row, rowValue);
};
break;
}
for (int i = 1; i <= rows; i++)
{
rowLoop(i);
}
return values;
}
And then to call it with...
var spreadsheetValues = GenerateValues("Employer", 5);
Then intention for the code is to have some base values stored in a List<string>, then depending on what entityType is passed into the method, add some additional values to those base values. Then loop round a certain number of rows to create the Dictionary<int, List<string>>, where int is the row number.
The issue I'm having is that baseValues is being updated during each iteration of my for loop. I didn't expect this when using var rowValue = baseValues;
This is a debug screenshot of the last item in the collection....
I am expecting each List<string> in Dictionary<int, List<string>> to contain 8 items, but instead it is growing with each iteration.
Why is this occurring and how might I correct it?

It seems like you are already on track with the solution to your problem but here is a way to solve it.
Where you write
var rowValue = baseValues;
you are really just making "rowValue" a pointer to "baseValues". To make a copy, you could do something like this:
var rowValue = baseValues.ToList();

All permutations of form options

I'm trying to test a form by submitting a combination of all values to see if it breaks. These are ComboBoxes that I have stored in an ExtraField class
public class ExtraField
{
public String Name = ""; //name of form key
public Dictionary<String, String> Options = new Dictionary<String, String>(); //Format: OptionText, Value
}
I have generated a list of these fields
List<ExtraField> efList = new List<ExtraField>();
I was thinking all possible combinations of these fields could be added to a string list that I can parse (I was thinking name=opt|name=opt|name=opt). I've provided an example of what would work below (where ExtraField list Count==3):
List<ExtraField> efList = new List<ExtraField>();
ExtraField f1 = new ExtraField();
f1.Name = "name1";
f1.Options.Add("text", "option1");
f1.Options.Add("text2", "option2");
f1.Options.Add("text3", "option3");
efList.Add(f1);
ExtraField f2 = new ExtraField();
f2.Name = "name2";
f2.Options.Add("text", "option1");
f2.Options.Add("text2", "option2");
f2.Options.Add("text3", "option3");
f2.Options.Add("text4", "option4");
efList.Add(f2);
ExtraField f3 = new ExtraField();
f3.Name = "name3";
f3.Options.Add("text2", "option1");
f3.Options.Add("text3", "option2");
f3.Options.Add("text4", "option3");
f3.Options.Add("text5", "option4");
f3.Options.Add("text6", "option5");
efList.Add(f3);
Should produce
name1=option1|name2=option1|name3=option1
name1=option1|name2=option1|name3=option2
name1=option1|name2=option1|name3=option3
name1=option1|name2=option1|name3=option4
name1=option1|name2=option1|name3=option5
name1=option1|name2=option2|name3=option1
name1=option1|name2=option2|name3=option2
name1=option1|name2=option2|name3=option3
name1=option1|name2=option2|name3=option4
name1=option1|name2=option2|name3=option5
name1=option1|name2=option3|name3=option1
name1=option1|name2=option3|name3=option2
name1=option1|name2=option3|name3=option3
name1=option1|name2=option3|name3=option4
name1=option1|name2=option3|name3=option5
name1=option1|name2=option4|name3=option1
name1=option1|name2=option4|name3=option2
name1=option1|name2=option4|name3=option3
name1=option1|name2=option4|name3=option4
name1=option1|name2=option4|name3=option5
name1=option2|name2=option1|name3=option1
...etc
All ExtraFields in the list need to have a value and I need all permutations in one format or another. It's a big list with a lot of permutations otherwise I'd do it by hand.

Well I did it... But I'm not proud of it. I'm sure there is a better way of doing it recursively. Hopefully this helps someone.
public List<String> GetFormPermutations(List<ExtraField> inList)
{
List<String> retList = new List<String>();
int[] listIndexes = new int[inList.Count];
for (int i = 0; i < listIndexes.Length; i++)
listIndexes[i] = 0;
while (listIndexes[inList.Count-1] < inList.ElementAt(inList.Count-1).Options.Count)
{
String cString = "";
//after this loop is complete. a line is done.
for (int i = 0; i < inList.Count; i++) {
String key = inList.ElementAt(i).Name;
Dictionary<String, String> cOptions = inList.ElementAt(i).Options;
String value = cOptions.ElementAt(listIndexes[i]).Value;
cString += key + "=" + value;
if (i < inList.Count - 1)
cString += "|";
}
retList.Add(cString);
listIndexes[0]++;
for(int i = 0; i < inList.Count -1; i++)
{
if (listIndexes[i] >= inList.ElementAt(i).Options.Count)
{
listIndexes[i] = 0;
listIndexes[i + 1]++;
}
}
}
return retList;
}

UPDATED ANSWER
So I managed to do it recursively. I haven't done this since college :D
Here's the whole class:
https://gist.github.com/Rastamas/8070ae7e1471d2183451a17bcf061376
PREVIOUS ANSWER BELOW
This goes through your list and adds the strings to a StringBuilder in the format you showed
foreach (var item in efList)
{
foreach (var option in item.Options)
{
stringBuilder.Append(String.Format("{0}={1}|", item.Name, option.Value));
}
stringBuilder.Remove(stringBuilder.Length - 1, 1);
stringBuilder.AppendLine();
}
Then you can just use stringBuilder.ToString() to get the whole list.

How do I make List of Lists? And then add to each List values?

class ExtractLinks
{
WebClient contents = new WebClient();
string cont;
List<string> links = new List<string>();
List<string> FilteredLinks = new List<string>();
List<string> Respones = new List<string>();
List<List<string>> Threads = new List<List<string>>();
public void Links(string FileName)
{
HtmlDocument doc = new HtmlDocument();
doc.Load(FileName);
foreach (HtmlNode link in doc.DocumentNode.SelectNodes("//a[#href]"))
{
HtmlAttribute att = link.Attributes["href"];
if (att.Value.StartsWith("http://rotter.net/forum/scoops1"))
{
links.Add(att.Value);
}
}
for (int i = 0; i < links.Count; i++)
{
int f = links[i].IndexOf("#");
string test = links[i].Substring(0, f);
FilteredLinks.Add(test);
}
for (int i = 0; i < FilteredLinks.Count; i++)
{
contents.Encoding = System.Text.Encoding.GetEncoding(1255);
cont = contents.DownloadString(FilteredLinks[i]);
GetResponsers(cont);
}
}
private void GetResponsers(string contents)
{
int f = 0;
int startPos = 0;
while (true)
{
string firstTag = "<FONT CLASS='text16b'>";
string lastTag = "&n";
f = contents.IndexOf(firstTag, startPos);
if (f == -1)
{
break;
}
int g = contents.IndexOf(lastTag, f);
startPos = g + lastTag.Length;
string responser = contents.Substring(f + firstTag.Length, g - f - firstTag.Length);
foreach (List<string> subList in Threads)
{
}
}
}
}
I created this variable :
List<List<string>> Threads = new List<List<string>>();
The first thing I don't know yet how to do is how to create inside Threads number of Lists according to the FilteredLinks.Count inside the Links method.
Second thing is in the GetResponsers method I did:
foreach (List<string> subList in Threads)
{
}
But what I want is that first time it will add all the values from variable responser to the first List in Threads. Then when it's getting to the break; it stop then and then in the Links methods its calling GetResponsers(cont); again this time I want that all the values in responser to be added to the second List in Threads.
I know that each time it's getting to the break; it will get the next FilteredLink from FilteredLinks.
How do I create number of Lists in Threads according to the FilteredLinks.Count?
How do I make the code in GetResponsers to add the responser ?

You don't need to specify the count for the number of lists in Threads, since it is a list, you can simply keep adding lists to it. So the first part is correct where you are declaring it.
The second part --> Your calling method will change. Look below for the calling method.
The third part --> Change private void GetResponsers(string contents) to private void GetResponsers(List threadList, string contents). Look below for implementation change.
Also the loop will look like this then
//other code you have
List<List<string>> Threads = new List<List<string>>();
public void Links(string FileName)
{
// ...other code you have
for (int i = 0; i < FilteredLinks.Count; i++)
{
threads.Add(new List<string>);
contents.Encoding = System.Text.Encoding.GetEncoding(1255);
cont = contents.DownloadString(FilteredLinks[i]);
GetResponsers(threads[threads.Count - 1], cont);
}
}
private void GetResponsers(List<string> threadList, string contents)
{
int f = 0;
int startPos = 0;
while (true)
{
string firstTag = "<FONT CLASS='text16b'>";
string lastTag = "&n";
f = contents.IndexOf(firstTag, startPos);
if (f == -1)
{
break;
}
int g = contents.IndexOf(lastTag, f);
startPos = g + lastTag.Length;
string responser = contents.Substring(f + firstTag.Length, g - f - firstTag.Length);
threadList.Add(responser);
}
}
PS: Please excuse the formatting.

How do i make List of Lists ? And then add to each List values?
The following codesnippet demonstrates you, how to handle List<List<string>>.
List<List<string>> threads = new List<List<string>>();
List<string> list1 = new List<string>();
list1.Add("List1_1");
list1.Add("List1_2")
threads.Add(list1);
List<string> list2 = new List<string>();
list1.Add("List2_1");
list1.Add("List2_2")
list1.Add("List2_3")
threads.Add(list2);
How do i create number of Lists in Threads according to the
FilteredLinks.Count ?
for(int i = 0; i < FilteredLinks.Count; i++)
{
var newList = new List<string>();
newList.Add("item1"); //add whatever you wish, here.
newList.Add("item2");
Threads.Add(newList);
}
I'm afraid I can't help you with Question #2, since I don't understand what you try to achieve there exactly.