c# - Saving parameters in a textfile

Question

I'm making a program that catalogs the names of the people I add in a listbox and save all the content to a file when you close the program.
Each line of the file is for a person:

Tommy
Marco
James
Dylan

When the program starts, the file data is loaded and add the names to listbox.
All this works great, but now I'm having trouble making something else.
Each person on the list need a variable to indicate whether it has paid and I want to save this variable together with his name on the file.
For this, I have:

bool paid;
private void checkbox_Paid_CheckedChanged(object sender, EventArgs e)
{
    paid = true;
}

I have only one checkbox, and it needs to differ from each person in the listbox, according to the selected in the event:

private void listDOF_SelectedIndexChanged(object sender, EventArgs e)
{

}

But I do not know how to write this bool in the file for each person, save to the file together with name and load it.
I've tried something like:

foreach(string purchasers in listDOF.Items)
{
    arq.WriteLine(purchases, paid);
}

Obviously this do not worked, I do not know how to assign the bool for each one of the purchasers and write it in the file.
I'm using .NET 4.5 in a WFA.
Thanks all in advance, if I able to do this, I will give a big step toward the knowledge.

Answer 1

First of all I would store the persons in a list in the application otherwise you will only have one bool for all the persons in the application and everyone will be set as payed or not payed.

public class Person
{
   public string Name { get; set; }
   public bool Payed { get; set; }
}

public List<Person> Persons { get; set; }

As simple way is to save it in a SCV file. Semicolons between fields and new row per post

Tommy; true
Marco; true

Then save like this

foreach(var person in Persons)
{ 
   arq.WrtieLine("{0};{1}", person.Name, person.Payed);
}

Answer 2

I believe that this is a good case to turn your text file into JSON.

For example:

[
  { name: "Tom", hasPaid: true },
  { name: "Matias", hasPaid: false } // Urgh!
]

And In C# you can build up this JSON using anonymous objects:

List<object> people = new List<object>();
people.Add(new { Name = "Tom", HasPaid = true });

Finally, you can serialize to JSON using JSON.NET:

File.WriteAllText(@"C:\myfile.json", JsonConvert.SerializeObject(people));

...or deserialize it:

List<object> people = JsonConvert.DeserializeObject<List<object>>(File.ReadAllText(@"C:\myfile.json"));

Update

Maybe you should use an concrete class rather than an anoymous object, because the later is inmutable and you're going to get in troubles if you need to data-bind the object list to the whole ListBox.

You can declare a simple class like this:

public class Person 
{
    public string Name { get; set; }
    public bool HasPaid { get; set; }
}

...add persons this way:

List<Person> people = new List<Person>();

Person person = new Person();
person.Name = "Tom";
person.HasPaid = true;
people.Add(person);

File.WriteAllText(@"C:\myfile.json", JsonConvert.SerializeObject(people));

And when it comes to deserializing the whole JSON array:

List<Person> people = JsonConvert.DeserializeObject<List<Person>(File.ReadAllText(@"C:\myfile.json"));

Update 2

It seems like you don't know you can bind a list to Windows Forms controls. See for example the following MSDN article.

Instead of List<T> you can use BindingList<T>. Check this CodeProject guide.

This way, when you add an item to the whole BindingList<T> the ListBox control will be automatically populated. If you remove one, it will also dissapear from the UI.

Both Windows Forms and Windows Presentation Foundation are powerful and productive if you leverage data-binding (also in Web development, say KnockoutJS!).