What is my Combobox_SelectedIndexChanged mistake?

Question

I want to set the values of my selected item in my combo box to a variable(person) so that I can compare a person value to a value in my sqlite database. Here is my code:

private void cboSelectClient_SelectedIndexChanged(object sender, EventArgs e)
{
    string str;
    personSearch = new Person();
    selectedPersonList = new List<Person>();

My problem is in the next line, where it should set my person variable items equal too the items that is in the combobox.

    personSearch = cboSelectClient.SelectedItem as Person;

   _pBl.PopulateSelectedPersonList(personSearch, ref selectedPersonList);  

   foreach (Person person in selectedPersonList)
   {
       txtAge.Text = Convert.ToString(person.Age);
       txtEmail.Text = person.Email;
       txtFirstName.Text = person.FirstName;
       txtID.Text = Convert.ToString(person.ID);
       txtLastName.Text = person.LastName;

       lstItemsAdded.Items.Add(person.Item);
   }      
}

This is how i populate my combobox:

foreach (Person PersonItem in _listAllData)
{
     if (PersonItem.FirstName != equalPerson.FirstName) //Add name en add  nie die name wat klaar in is nie... VIND UIT HOE OM NET N SEKERE DEEL TE ADD..
     {
         cboSelectClient.Items.Add(PersonItem.ID +" : "
            + PersonItem.FirstName + " " 
            + PersonItem.LastName + " " 
            + PersonItem.Age + " " 
            + PersonItem.Email + " " 
            + PersonItem.Item.ItemCode 
            + " " + PersonItem.Item.ItemDescription 
            + " " + PersonItem.Item.ItemName + " " 
            + PersonItem.Item.ItemPrice);

      }

      equalPerson = PersonItem;
}

What is the error or unexpected behavior that you are getting? — Jon Senchyna, Feb 07 '14 at 12:34
Why are you assigning a new instance of `Person` to `personSearch` when you are changing its reference without using that variable beforehand? — Kapol, Feb 07 '14 at 12:35
when it comes to this line: personSearch = cboSelectClient.SelectedItem as Person; it does not set my personSearch values to anything — user2980509, Feb 07 '14 at 12:35
If that is the case, then the current issue is in how you are populating your ComboBox. Show us the code for that and we may be able to help you. — Jon Senchyna, Feb 07 '14 at 12:36
Have a [look here](http://stackoverflow.com/a/21552919/2596334) it might give you a some ideas. — Scott Solmer, Feb 07 '14 at 12:37
Seems like your adding a string to the combobox, but expecting an object to come out... — Scott Solmer, Feb 07 '14 at 12:41
How do i add an object into the combobox, is it just cbobox.items.add(person);? and if i only want to add certain properties of that person into the text of the combo box can i use: combobox.text = ("text");? — user2980509, Feb 07 '14 at 12:45

score 1 · Accepted Answer · answered Feb 07 '14 at 12:42

Problem here is that you are populating your ComboBox with string, not with actual Person object. Of course this string cannot be converted directly back to object, therefore your conversion fails and personSearch is assigned to null.

To resolve the issue you need to:

Populate ComboBox with actual Person objects. Make sure ComboBox.ValueMemeber is null.
In Person class define some property like Text and set DisplayMember to it or override ToString to control how entries in CombobBox appear on the UI

What is my Combobox_SelectedIndexChanged mistake?

1 Answers1