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I have two list boxes ,one works on UI thread and another I need to work on another thread.First List box is populated with UI thread,after adding the full elements I need to add those elements into another list box using another .What should I do for this.I have codded for this but I get an error like Invoke or BeginInvoke cannot be called on a control until the window handle has been created. I may put code snippet I have written

Rajeesh
Thanks and Regards

C#
using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;

namespace ThreadApplication
{
    public partial class Form1 : Form
    {
       
        public Form1()
        {
            InitializeComponent();
         
        }


        private void button1_Click(object sender, EventArgs e)

        {
            try
            {
            label1.Text = Thread.CurrentThread.Name;
            string[] fruits;
            fruits = new string[5];
            fruits[0] = "Banana";
            fruits[1] = "Grape";
            fruits[2] = "Apple";
            fruits[3] = "Orange";
            fruits[4] = "Pappaya";

            foreach (var fruit in fruits)
            {
                listBox1.Items.Add(fruit);
                listBox1.Refresh();
            }

            var list = new ArrayList();
            list.AddRange(listBox1.Items);

             Thread  objNewThread = new Thread(new ParameterizedThreadStart(objAddFruits.ConsumerJob));
             
             objNewThread.Start(list);     
            
             Thread.Sleep(1000);

             MessageBox.Show("" + Thread.CurrentThread.Priority);
        

            }
            catch (Exception ex)
            {
                MessageBox.Show("" + ex.Message);
                throw;
            }

        }

        private void button2_Click(object sender, EventArgs e)
        { 
           //new ConsumerJobClass().ConsumerJob();
            
        }
      
        }



    public  class ConsumerJobClass :Form1
    {

        public  void ConsumerJob(object list)
        { 
            var frm=new Form1();
            
           ArrayList arrayList=(ArrayList)list;
         foreach (var item in arrayList)
            {
               if (!frm.IsHandleCreated)
                    frm.CreateControl();
 frm.listBox2.Invoke((MethodInvoker)delegate() { frm.listBox2.Items.Add(item); }); // I got Error here
                listBox2.Refresh();
                this.Invoke(new Action(() => listBox1.Items.Remove(item)));
                listBox1.Items.Remove(item);
                listBox1.Refresh(); 
               
             }

        }

    }


    }
Posted
Updated 16-Apr-14 0:15am
v2

1 solution

Don't even try to do it like that.
For starters, it won't work: you create a new instance of the form in your ConsumerJob method, so even if it did work it wouldn't update the display.

Instead, consider using a BackgroundWorker class instead: it provides a mechanism for feeding progress back to the form that originated the thread via the ProgressChanged Event, and that infor can include the e.UserState object - which can contain the data you want to update the listboxes with.
 
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