Question

The situation is that I have 2 controls, a text box and a combo box. The user can select something in the combo box, it fills the text box with the value member, if the user types into the text box, I want to check if it exists in the combo box’s values and then select the corresponding display member.

The method I was expecting to be there was something like

if(cmb1.valueMembers.Contains(txt1.Text))

but I can’t find anything like this, I also thought looping through them could find it? so I’ve got

foreach (System.Data.DataRowView row in cmb1.Items)
        {}

but can’t find the value member anywhere in the row?

Thanks

Answer 1

Ok, here’s a simple example but I guess that’s the main idea. We have a MyClass which have Id for the ValueMember and Name for the DisplayMember.

 public partial class Form1 : Form
{
    class MyClass
    {
        public MyClass(string name, int id)
        {
            Name = name;
            Id = id;
        }
        public string Name { get; set; }
        public int Id { get; set; }
    }

    List<MyClass> dsList = new List<MyClass>();

    public Form1()
    {

        for (int i = 0; i < 10; i++)
        {
            dsList.Add(new MyClass("Name" + i , i));
        }

        InitializeComponent();

        comboBox1.DataSource = dsList;
        comboBox1.ValueMember = "Id";
        comboBox1.DisplayMember = "Name";
    }

    private void textBox1_TextChanged(object sender, EventArgs e)
    {
        //Checks if item with the typed Id exists in the DataSource
        // and selects it if it's true
        int typedId = Convert.ToInt32(textBox1.Text);
        bool exist = dsList.Exists(obj => obj.Id == typedId);
        if (exist) comboBox1.SelectedValue = typedId;

    }


    private void comboBox1_SelectedValueChanged(object sender, EventArgs e)
    {
        MyClass obj = comboBox1.SelectedValue as MyClass;
        if (obj != null) textBox1.Text = obj.Id.ToString();
    }
}

Feel free to ask if something’s not clear.

PS: In the example I’m assuming that integers will be typed in the textbox