Sort .txt in c++/cli - sorting

Question

I have a few lines of saved strings into a text file in no particular order and the person I'm making this little software for is asking me to sort every item's ID when loading the saved data. Thing is I absolutely no idea where to start or how to do it. I've looked everywhere but couldn't anything to fix my issue.
First things first I am very new to saving files so my saved data is clunky. It is written line by line and divided by spaces, example :
1020 lenovo-laptop FirstName LastName
xxxx xxxxx FirstName LastName
It needs to be sorted by IDs, line by line. It already loads in a listbox, I think I have the loading part working perfectly, only need it to be sorted out.
Here is my loading function:
private: System::Void btn_load_Click(System::Object^ sender, System::EventArgs^ e) {
lst_relier->Items->Clear();
String^ fileName = "save.txt";
try
{
StreamReader^ read = File::OpenText(fileName);
String^ str;
int count = 0;
while ((str = read->ReadLine()) != nullptr)
{
count++;
Console::WriteLine("line {0}: {1}", count, str);
// MessageBox::Show(str);
lst_relier->Items->Add(str);
}
}
catch (Exception^ e)
{
if (dynamic_cast<FileNotFoundException^>(e))
Console::WriteLine("Fichier introuvable", fileName);
else
Console::WriteLine("Erreur de chargement", fileName);
}
}
This software is nothing too serious, I'm an intern in a company and I'm making this for my friends personal use in the company. It doesn't need to be top notch performing, it needs to work properly though.
Any help would be greatly appreciated, thank you!

Answer 1

Create domain model class:
public ref class Item
{
private:
static int Sort(Item^ item1, Item^ item2)
{
return item1->Id.CompareTo(item2->Id);
}
public:
property int Id;
property String^ Title;
property String^ FirstName;
property String^ LastName;
static Comparison<Item^>^ comparison = gcnew Comparison<Item^>(&Sort);
};
Declare generic list into your Form class:
List<Item^>^ items = gcnew List<Item^>(); // form field
Read from file, parse and populate the collection:
StreamReader^ read = File::OpenText(L"save.txt");
String^ str;
while ((str = read->ReadLine()) != nullptr)
{
array<String^>^ splitted = str->Split();
Item^ item = gcnew Item();
item->Id = int::Parse(splitted[0]);
item->Title = splitted[1];
item->FirstName = splitted[2];
item->LastName = splitted[3];
items->Add(item);
}
read->Close();
dataGridView1->DataSource = items;
At the end bind list to UI control. I suggest to use DataGridView instead of ListBox. Imho, it is more visually.
When you need the data to sort:
items->Sort(Item::comparison);
dataGridView1->DataSource = nullptr;
dataGridView1->DataSource = items;
Call the Sort method and make rebinding.