Serialization

Question

How to save information from Listview in bin file? When adding new records, I was able to serialize, but I can’t save the existing one

Answer 1

How to save information from Listview in bin file? When adding new records, I was able to serialize, but I can’t save the existing one

public partial class bibliography : Form
{
string fileName = "data.dat";
AddBook frm;

public bibliography()
{
InitializeComponent();
}

private void OpenFile_Click(object sender, EventArgs e)
{
var dlg = new OpenFileDialog();

if (dlg.ShowDialog() == DialogResult.OK)
{
fileName = dlg.FileName;
LoadFromFile();
}
}

private void LoadFromFile()
{
var f1 = new FileStream(fileName, FileMode.OpenOrCreate);

var bf = new BinaryFormatter();

while (f1.Position < f1.Length)
{
var b = (Book)bf.Deserialize(f1); // сохранение объекта в потоке f
AddBookToList(b);
}
f1.Close();
}

private void AddBookToList(Book b)
{
var item = listView.Items.Add(b.Author);
item.SubItems.Add(b.Name);
item.SubItems.Add(b.Year.ToShortDateString());
item.SubItems.Add(b.PublishingOffice);
}

private void MenuAdd_Click(object sender, EventArgs e)
{
frm = new AddBook();

if (frm.ShowDialog() == DialogResult.OK)
{
AddBookToList(frm.Book);
SaveAdd(frm, e);
}
}
private void SaveAdd(object sender, EventArgs e)
{
if (listView.Items.Count > 0)
{
var f1 = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);
f1.Position = f1.Length;

var bf = new BinaryFormatter();
bf.Serialize(f1, frm.Book); // сохранение объекта в потоке f

f1.Close();
}

Answer 2

A object is not the same a a text.

If you have a text, you can append to it.

If you are serializing a object, it is a structure.

If you want to save the new state of Book.
Create a new file / overwrite the existing one
Save the entire object

Use FileMode.Open, set f1.Position to 0