Working with combox and listbox in WPF

Avuya Mxoli

Hi all,

I have a combobox with cities and a listbox for customers.

When I select a city, I display all customers who stay there in my listbox. The problem is that when I select a city and the customers get loaded, and I select the same city again it adds the customers again. Is there a way where I can avoid repeating items in a listbox?

I hope this is clear, thanks in advance

5 Replies

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Satyapriya Nayak14y ago
Accepted answer
Hi Avuya,

Try this...

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace WindowsFormsApplication1

{



    public partial class Form1 : Form
    {

        public Form1()

        {

            InitializeComponent();

        }

        private void Form1_Load(object sender, EventArgs e)
        {

            listBox1.Items.Add("Raj");

            listBox1.Items.Add("Raj");

            listBox1.Items.Add("Raju");

            listBox1.Items.Add("Rahul");

            listBox1.Items.Add("Harry");

            listBox1.Items.Add("Ben");

            listBox1.Items.Add("Ian");

        }





        private void btn_right_Click(object sender, EventArgs e)
        {

            if (listBox2.Items.Contains(listBox1.SelectedItem) == true)
            {

                MessageBox.Show("Item Exits");

            }

            else

            {

                listBox2.Items.Add(listBox1.SelectedItem);

                int i = 0;
                i = listBox1.SelectedIndex;

                listBox1.Items.RemoveAt(i);

            }

        }

        private void btnleft_Click(object sender, EventArgs e)
        {

            listBox1.Items.Add(listBox2.SelectedItem);

            int i = 0;

            i = listBox2.SelectedIndex;

            listBox2.Items.RemoveAt(i);

        }

    }

}

Thanks
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Avuya Mxoli14y ago
Thanks Priya it works but only if I move them one by one. I have a button that moves listbox1 items to 2nd listbox all at the same time but here I cannot avoid adding all these items twice. It just doesnt work Im using this:if(lbx1.items.contains(lbox2.items) == true) { MessageBox.Show("Items exist"); } it just skips the if statement...
Vulpes14y ago
Something like this perhaps:

if (listBox1.SelectedIndex > -1 && !listBox2.Items.Contains(listBox1.SelectedItem))
{
listBox2.Items.Add(listBox1.SelectedItem);
}
Avuya Mxoli14y ago
Actually I realized I already sorted that out, now what I want to know is if I add a 2nd listbox where items will be added from the 1st one, how can I prevent adding duplicate items to the 2ns listbox. Example: I select a customer from listbox1 and add to listbox2, then I re-select the city from combobox and the customers get re-added to 1st listbox and the user selects a cusomer thats already in listbox2 and tries to add them again. How do I prevent this?
Vulpes14y ago
You need to clear the listbox's Items collection before loading the next set of customers:

listBox1.Items.Clear();