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c#comboboxselecteditemselectedvalueselectedindexchanged

Getting selected value of a combobox


public class ComboboxItem { 
            public string Text { get; set; } 
            public string Value { get; set; }
            public override string ToString() { return Text; } 
        }

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            int selectedIndex = comboBox1.SelectedIndex;
            int selecteVal = (int)comboBox1.SelectedValue; 
            ComboboxItem selectedCar = (ComboboxItem)comboBox1.SelectedItem;
            MessageBox.Show(String.Format("Index: [{0}] CarName={1}; Value={2}", selectedIndex, selectedCar.Text, selecteVal));
        }

I'm adding them like:

ComboboxItem item = new ComboboxItem();
                    item.Text = cd.Name;
                    item.Value = cd.ID;
                    this.comboBox1.Items.Add(item);

I keep getting a NullReferenceExeption and not sure why. the text seems to show up just fine.


Solution

  • Try this:

    private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        ComboBox cmb = (ComboBox)sender;
        int selectedIndex = cmb.SelectedIndex;
        int selectedValue = (int)cmb.SelectedValue;
    
        ComboboxItem selectedCar = (ComboboxItem)cmb.SelectedItem;
        MessageBox.Show(String.Format("Index: [{0}] CarName={1}; Value={2}", selectedIndex, selectedCar.Text, selecteVal));        
    }