I'm trying to fill my List from a text file using C#?

Question

I have a class called cEspecie like this

public class cEspecie
{
    private string name;
    private int lifetime;
    private int movility;
    private int deadto;
    private int type;

public string Name
    {
        get
        {
            return name;
        }
        set
        {
            name= value;
        }
    }
public int Type
    {
        get
        {
            return type;
        }
        set
        {
            type = value;
        }
    }
public int LifeTime
    {
        get
        {
            return lifetime;
        }
        set
        {
            lifetime= value;
        }
    }
public int Movility
    {
        get
        {
            return movility;
        }
        set
        {
            movility = value;
        }
    }
public int DeadTo
    {
        get
        {
            return deadto;
        }
        set
        {
            deadto = value;
        }
    }
}

I store some data in a list called

List<cEspecie> list = new List<cEspecie>() { 
new cEspecie("Wolf", 100, 10, 0, 0)
new cEspecie("Rabiit", 100, 100, 1, 1), 
new cEspecie("Lion", 200, 10, 2, 2), 
new cEspecie("Tiger", 300, 10, 3, 3),  
};

In one of the process of my program i store all the data inside a text file using this:

using (StreamWriter sr = new StreamWriter(@"../../Archives/TextFilecEspecie.txt"))
        {
            foreach (var item in list)
            {   
                sr.WriteLine(item.Name);
                sr.WriteLine(item.Type);
                sr.WriteLine(item.Movility);
                sr.WriteLine(item.LifeTime);
                sr.WriteLine(item.DeadTo);
            }
            sr.Close();
        }

the result inside "TextFilecEspecie.txt" was this:

Wolf
100
10
0
0
Rabiit
100
100
1
1
Lion
200
10
2
2
Tiger
300
10
3
3

now my real, real problem is ... How can i get back the same data to store it in the same list? I'm using c# and wpf and i really dont find an answer.

What have you tried? What don't you understand? Are you asking how to read a line from a text file? How to convert a string to a number? How to loop through the file? — SLaks, Nov 22 '13 at 20:06
Actually due to the properties of the class, I dont know how to assign them to each one while reading the text file. — user3023107, Nov 22 '13 at 20:08
Maybe you should have delimited the objects to one line then you read each line and `Split` the line on the delimiting char and rebuild your objects. — OneFineDay, Nov 22 '13 at 20:08
as a sidenote calling sr.Close() is not necessary and should be avoided if you use the using statement — Fabio Marcolini, Nov 22 '13 at 20:22

Cory Nelson · Answer 1 · 2013-11-22T20:26:31.377

5

Using LINQ, and the Buffer extension method from Microsoft's excellent Ix-Main package.

var species = File.ReadLines("file.txt")
                .Buffer(5)
                .Select(x => new cEspecie
                {
                    Name = x[0],
                    Type = int.Parse(x[1]),
                    Movility = int.Parse(x[2]),
                    LifeTime = int.Parse(x[3]),
                    DeadTo = int.Parse(x[4])
                });

Buffer(5) will group every 5 lines into an array.

edited Nov 22 '13 at 20:26

answered Nov 22 '13 at 20:15

Cory Nelson

29,236
5
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110

Instead of Buffer, you can use implementation from the answer: http://stackoverflow.com/questions/419019/split-list-into-sublists-with-linq – Dariusz Woźniak Nov 22 '13 at 20:36

score 2 · Answer 2 · edited May 23 '17 at 10:31

2

This is what serialization and ISerializable are for.

Here is a quick tutorial that should make it fairly simple.

I might even recommend JSON.Net, which will write it in JSON format so you could more easily create/edit the objects in the file.

edited May 23 '17 at 10:31

Community

1
1

answered Nov 22 '13 at 20:13

Erik Kerber

5,646
7
38
56

score 1 · Answer 3 · answered Nov 22 '13 at 20:07

1

You do the same thing only backwards using StreamReader to read the file. I won't get into specifics since I'm guessing you can use the learning experience so consider this a point to the right direction and homework :)

answered Nov 22 '13 at 20:07

System Down

6,192
1
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Fabio Marcolini · Accepted Answer · 2013-11-22T20:17:56.130

you can do that this way

        var list = new List<cEspecie>();
        using (StreamReader reader = File.OpenText(filePath))
        {
            while(!reader.EndOfStream)
            {
                string name = reader.ReadLine();
                int type = int.Parse(reader.ReadLine());
                int movility = int.Parse(reader.ReadLine());
                int lifeTime = int.Parse(reader.ReadLine());
                int deadTo = int.Parse(reader.ReadLine());
                list.Add(new cEspecie(name, type, movility, lifeTime, deadTo));
            }
        }

note that:

int.Parse throw error if the string is not a int, use TryParse the data may not be a int
this work only if the file has the correct number of lines

score 0 · Answer 5 · answered Nov 22 '13 at 20:10

0

var list = File.ReadLines("path").Select(x => new cEspecie(x));

in cEspecie constructor you can initialize the object using input line.

answered Nov 22 '13 at 20:10

Mayank

8,777
4
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60

1

@FabioMarcolini This gives you a `List` not a list `List`... It's the cleanest way to read the file but is far from solving the problem. Also, give the format of the input this isn't a usable solution. If each object was like comma delimited on a single line you could use `ReadAllLines` then do `Select(x => x.Split(',')` then pass the tokens into a constructor and make alist of objects but the way he's readying the ifle doesn't allow for that. – evanmcdonnal Nov 22 '13 at 20:12

score 0 · Answer 6 · answered Nov 22 '13 at 20:15

Something like this is very simple and should work. Do error checking though.

List<cEspecie> list = new List<Persona>();  
string[] readText = File.ReadAllLines(@"../../Archives/TextFilecEspecie.txt");

for(int i=0;i<readText.Length/5;i++)
{
    list.Add(new Persona(readText[i*5], readText[i*5+1], readText[i*5+2], readText[i*5+3], readText[i*5+4]));
}

I'm trying to fill my List from a text file using C#?

6 Answers6