System.ArgumentException：“设置 DataSource 属性时无法修改项目集合。” C# Windows Forms

Question

So I'm trying to take combobox and textbox input values from the current form and add them to a listbox on the following form. However I get the following error

System.ArgumentException: 'Items collection cannot be modified when the DataSource property is set.'

I've tried to make the datasource = null 'listbox1.DataSource = null;' and clear the listbox contents 'listbox1.Items.Clear();'. However, when I proceed to the next form the to see the saved values, the values are invisible in the listbox. However, all of the inputs are saved to the sql database.

Modified Method

Output

Any help would be highly appreciated.

Code Block related to the issue

@aepot I have followed your code example and still seem to get the empty listbox. Also, if I use AccountInfo which is my property class instead of string then the exception from before comes back. I'm not sure what else can be done at this point. AccountInfo Class Adjusting Comparisson Result Outcome

@aepot Here is the code if you're still interested in helping DataAccess Class

public void InsertNewCardDetails(string card_Type, string card_Number, string expiry_date, string _ccv, string _duration)
        {
            using (IDbConnection connection = new System.Data.SqlClient.SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\nauri\source\repos\StylistsApp\Database\UserAccountDatabase.mdf;Integrated Security=True;Connect Timeout=30"))
            {
                List<AccountInfo> accounts = new List<AccountInfo>();
                accounts.Add(new AccountInfo {cardType = card_Type, cardNumber = card_Number, expiryDate = expiry_date, ccv = _ccv, duration = _duration });
                connection.Execute("INSERT INTO[Table] (cardType, cardNumber, expiryDate, ccv, duration) VALUES(@cardType, @cardNumber, @expiryDate, @ccv, @duration)", accounts);
            }
                 
        }

Here I'm just binding variables to input fields

  public partial class CardDetails : Form
    {
        public CardDetails()
        {
            InitializeComponent();
        }

        private void label4_Click(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {

            DataAccess db = new DataAccess();
            SetValueForCardType = comboBox1.SelectedItem.ToString(); 
            SetValueForCardNumber = textBox5.Text;
            SetValueForExpiryDate = textBox2.Text;
            SetValueForCCV = textBox3.Text;
            SetValueForDuration = comboBox2.SelectedItem.ToString();
            db.InsertNewCardDetails(comboBox1.SelectedItem.ToString(), textBox5.Text, textBox2.Text, textBox3.Text, comboBox2.SelectedItem.ToString());
            //MessageBox.Show("Account Created Successfully!");

            this.Close();
            Summary summary = new Summary();
            summary.Show();

        }
    

    
        public static string SetValueForCardType = "";
        public static string SetValueForCardNumber = "";
        public static string SetValueForExpiryDate = "";
        public static string SetValueForCCV = "";
        public static string SetValueForDuration = "";

Here I'm trying to retrieve info from the previous form

 public partial class Summary : Form
    {
        //List<AccountInfo> people = new List<AccountInfo>();
        private BindingList<string> items = new BindingList<string>();
        public Summary()
        {
            InitializeComponent();
        }
        private void Summary_Load(object sender, EventArgs e)
        {

            listBox1.DataSource = items;
        }
        private void button4_Click(object sender, EventArgs e)
        {

            SqlConnection sql = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\nauri\source\repos\StylistsApp\Database\UserAccountDatabase.mdf;Integrated Security=True;Connect Timeout=30");
            sql.Open();                                      
            SqlCommand sqa = new SqlCommand("Select cardType, cardNumber, expiryDate, ccv, duration from [Table] where email =@email", sql);
            sqa.Parameters.AddWithValue("@email", Form1.SetValueForText1);
            SqlDataReader da = sqa.ExecuteReader();
            while (da.Read())
            {
                items.Add("Hello");
                items.Add("World");
                items.Add(da.GetValue(2).ToString());
                items.Add(da.GetValue(3).ToString());
                items.Add(da.GetValue(4).ToString());

            }
            sql.Close();
        }

Answer 1

Try BindingList<T> as DataSource

private BindingList<string> items = new BindingList<string>();

Then assign the DataSource

listBox1.DataSource = items;

Then you can modify the Collection fluently

items.Add("Hello");
items.Add("World");

or

items.Clear();

ListBox will update its layout automatically.

Note: if you'll reassign new BindingList instance to items during the app execution, don't forget to reassign the DataSource then.

The same can be applied to any Control which has DataSource .

---

Edit

however, now when I enter the values to be displayed in listbox1, the listbox is blank but you can see the blue selected fields for each line in the listbox where text should appear

Cannot reproduce that. See the following code. To reproduce it in Designer I've just added a ListBox and a Button without any additional setup.

public partial class Form1 : Form
{
    private BindingList<string> items = new BindingList<string>();

    public Form1()
    {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        listBox1.DataSource = items;
    }

    private void button1_Click(object sender, EventArgs e)
    {
        items.Add("Hello");
        items.Add("World");
    }
}