Save a user's clicks in checkListBox

Question

In my app, I have a few of checkListBoxes and I need to save clicks on this list. That means for the next time I don't need to click on them again and again.

Code:

public Form2()
{
    InitializeComponent();
    InitializeSecondForm();
}

private void InitializeSecondForm()
{
    this.Height = Properties.Settings.Default.SecondFormHeight;
    this.Width = Properties.Settings.Default.SecondFormWidth;
    this.Location = Properties.Settings.Default.SecondFormLocation;

    this.FormClosing += SecondFormClosingEventHandler;
    this.StartPosition = FormStartPosition.Manual;
}

private void SecondFormClosingEventHandler(object sender, FormClosingEventArgs e)
{
    Properties.Settings.Default.SecondFormHeight = this.Height;
    Properties.Settings.Default.SecondFormWidth = this.Width;
    Properties.Settings.Default.SecondFormLocation = this.Location;

    Properties.Settings.Default.Save();
}

I tried to use this question for my answer, but it's not working: Save CheckedListBox Items to Settings

With a simple checkBox it's not a problem, but here we have a list.

Any idea how to do it?

Answer 1

Perhaps saving identifiers of each checked item to a json file.

In the following I did on CheckedListBox, for multiple CheckedListBox controls you need to adjust the code to use one json file with a modified structure to account for multiple CheckedListBox control or one json file per CheckedListBox.

Example, load items into the following class

public class Product
{
    public int ProductID { get; set; }
    public string ProductName { get; set; }
    public override string ToString()
    {
        return ProductName;
    }

}

Use the following class for read/write to a json file, in this case using json.net but will work also with system.text.json.

public class JsonOperations
{
    /// <summary>
    /// In your app you need to setup a different file name for each CheckedListBox
    /// </summary>
    public static string FileName => 
        Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Checked.json");

    /// <summary>
    /// Save only checked products
    /// </summary>
    /// <param name="list"></param>
    public static void Save(List<ProductItem> list)
    {
        string json = JsonConvert.SerializeObject(list, Formatting.Indented);
        File.WriteAllText(FileName, json);
    }

    /// <summary>
    /// Read back if file exists
    /// </summary>
    /// <returns></returns>
    public static List<ProductItem> Read()
    {
        List<ProductItem> list = new List<ProductItem>();

        if (File.Exists(FileName))
        {
            list = JsonConvert.DeserializeObject<List<ProductItem>>(File.ReadAllText(FileName));
        }

        return list;
    }
}

The following classes provide methods to get checked items set checked items from json mentioned above.

public static class CheckedListBoxExtensions
{
    public static List<ProductItem> IndexList(this CheckedListBox sender)
    {
        return
        (
            from item in sender.Items.Cast<Product>()
                .Select(
                    (data, index) =>
                        new ProductItem()
                        {
                            ProductID = data.ProductID,
                            Index = index
                        }
                )
                .Where((x) => sender.GetItemChecked(x.Index))
            select item
        ).ToList();
    }
    public static void SetChecked(this CheckedListBox sender, int identifier, bool checkedState = true)
    {
        var result = sender.Items.Cast<Product>()
            .Select((item, index) => new CheckItem
            {
                Product = item, 
                Index = index
            })
            .FirstOrDefault(@this => @this.Product.ProductID == identifier);

        if (result != null)
        {
            sender.SetItemChecked(result.Index, checkedState);
        }
    }
}

public class CheckItem { public Product Product { get; set; } public int Index { get; set; } }

Form code would resemble the following to read checked items on form shown event and save checked item on form closing event.

public partial class SaveItemsForm : Form
{
    private List<Product> _products = new List<Product>();
    public SaveItemsForm()
    {
        InitializeComponent();
        Shown += OnShown;
        Closing += OnClosing;
    }

    private void OnClosing(object sender, CancelEventArgs e)
    {
        List<ProductItem> checkedItems = ProductCheckedListBox.IndexList();
        if (checkedItems.Count > 0)
        {
            JsonOperations.Save(checkedItems);
        }
        else
        {
            JsonOperations.Save(new List<ProductItem>());
        }
    }

    private void OnShown(object sender, EventArgs e)
    {
        _products = SqlServerOperations.ProductsByCategoryIdentifier(1);

        ProductCheckedListBox.DataSource = _products;

        /*
         * Search for each product by id, if in the CheckedListBox check it
         */
        var items = JsonOperations.Read();
        if (items.Count >0 )
        {
            items.ForEach( x => ProductCheckedListBox.SetChecked(x.ProductID));
        }
    }
}