C#

private delegate bool UpdateHandle(int nValue,string text);
private UpdateHandle myUpdate = null;

BeeUpdate(int value, string text)

public bool BeeUpdate(int value, string text)
{
     LabelInfo.Text = text;
     LabelInfo.Refresh();
     if (value > 0)
     {
          if (Bar.Value + value < Bar.Maximum)
          {
               Bar.Value += value;
               Bar.Refresh();
               return true;
          }
          else
          {
               Bar.Value = Bar.Maximum;
               Bar.Refresh();
                    
               this.Close();
               return false;
          }
     }
     return false;
}

private void ShowProcessBar()
{
     myProcessBar = new ProgressBee("Uploading", 100 * ClassCount);
            
     myUpdate = new UpdateHandle(myProcessBar.BeeUpdate);

     myProcessBar.ShowDialog();

     myProcessBar = null;
}

//caller is the main window
public bool CopyTo(parm1, parm2,Form caller)
{
     MethodInvoker mi = new MethodInvoker(ShowProcessBar);

     mi.BeginInvoke(null, null);

     caller.BeginInvoke(mi);

     Thread.Sleep(2000);
            
     Thread copyProcess = new Thread(delegate()
     {
          for (int i = 0; i < FeatureClassCount; i++)
          {
               Thread.Sleep(30);

               if (condition)
               {
                    //the Interface of ArcEngine  upload data
               }
               else
               {
                    //another Interface of ArcEngine upload data

               }

               caller.Invoke(this.myUpdate, new object[] { 100, "……" });

          }
     });

     copyProcess.Priority = ThreadPriority.AboveNormal;
     copyProcess.Start();
     return true;
}