C#

Casper Hansen wrote:

while ((inputLine = reader.ReadLine()) == null)
{
listBox1.Items.Add(reader.ReadLine());
}

using System;
using System.Windows.Forms;

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

        // Event handler
        void FakeUIUpdater(string textboxText)
        {
            // Create a new delegate updater
            UIUpdaterDelegate updateUI = new UIUpdaterDelegate(UpdateUI);

            // Send the delegate to the winform
            this.Invoke(updateUI, new object[] { textboxText });
        }

        // Create the delegate
        delegate void UIUpdaterDelegate(string textboxText);

        // Update the user interface with the arguments set earlier in fakeuiupdater
        protected void UpdateUI(string textboxText)
        {
            textBox1.Text = textboxText;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            FakeUIUpdater("test");
        }
    }
}

if ((State == FormWindowState.Maximized) || (State == FormWindowState.Normal))
{
  if (!this.IsDisposed)
  {
    WindowState = FormWindowState.Minimized;
    Show();
  }
}
else if (State == FormWindowState.Minimized)
{
  if (!this.IsDisposed)
  {
    WindowState = FormWindowState.Minimized;
    Hide();
  }
}

private void MainForm_SizeChanged(object sender, EventArgs e) {
   if (this.WindowState == FormWindowState.Normal) {
      this.frmProgressBar.WindowState = FormWindowState.Normal;
      this.frmProgressBar.BringToFront();
   } else if ...
}

private frmProgressBar barForm; <-- at form level
private void ShowProgress() {
   barForm = new frmProgressBar();
   barForm.Show();
   ...
}
private void UpdateProgress(int percentage) {
   barForm.ProgressControl.Value = percentage;
   OR PREFERRABLY
   barForm.UpdatePercentage(percentage); <--- this method would update any necessary controls in frmProgressBar
   ...
}
private void EndProgress() {
   barForm.Hide();
   barForm = null;
   ...
}