错误：其他信息：设置DataSource属性时，不能修改项目集合

Question

I'm having this issue with a program that adds files to my combobox and also added to database.

I had 2 button add+ and - to delete the fields one by one on combobox

when i click ADD + button the data in my orm that means i have another combobox, lable,datetimepicker these are added in my FAVORITES combobox

combofavorite.Items.Add("Report Type: " + cmbreporttype.Text + " Date From: " + dateTimePicker1.Text + " To: " + dateTimePicker2.Text);
            combofavorite.SelectedIndex = 0;
            MessageBox.Show("Add Report Type: " + cmbreporttype.Text + " Date From: " + dateTimePicker1.Text + " To: " + dateTimePicker2.Text + " TO Favorite", "Added to Favorite", MessageBoxButtons.OK, MessageBoxIcon.Information);

Add the added data in the combobox is also added into database table

 MySqlConnection connection = new MySqlConnection(MyCon);
            MySqlCommand cmd = new MySqlCommand("INSERT INTO favorite (favorite) VALUES (@favo)", connection);
            cmd.CommandType = CommandType.Text;
            cmd.Parameters.AddWithValue("@favo", combofavorite.Text);
            connection.Open();
            cmd.ExecuteNonQuery();



 private void cmbfav_SelectedIndexChanged(object sender, EventArgs e)
        {
            string ID = cmbfav.SelectedValue.ToString();
        }

When i try this i got an error on here.

Plese help me to solve my problem .

Answer 1

@Anu Dont use combofavorite.Text in AddWithValue.

instead of this

     MySqlCommand cmd = new MySqlCommand("INSERT INTO favorite (favorite) VALUES (@favo)", connection);
     cmd.CommandType = CommandType.Text;
     cmd.Parameters.AddWithValue("@favo", combofavorite.Text);

use this:

      MySqlCommand cmd = new MySqlCommand("INSERT INTO favorite (favorite) VALUES (@favo)", connection);
      cmd.CommandType = CommandType.Text;
      cmd.Parameters.AddWithValue("@favo","Report Type: " + cmbreporttype.Text + " Date From: " + dateTimePicker1.Text + " To: " + dateTimePicker2.Text);

Hope it will help.