Using BackgroundWorker How do I pass parameters to the GUI Components?

public class Form1 : Form
{
   private ArrayList arrayList = new ArrayList();
   
   private BackgroundWorker backgroundWorker1 = new BackgroundWorker();
 
   public Form1()
   {
      backgroundWorker1.DoWork += new DoWorkEventHandler(backgroundWorker1_DoWork);
      backgroundWorker1.RunWorkerCompleted += new RunWorkerCompletedEventHandler(backgroundWorker1_RunWorkerCompleted);
 
   {
 
   private void btnSetTextBackgroundWorker_click(object sender, EventArgs e)
   {
      arrayList.Add("Happy");
      arrayList.Add(1);
      this.backgroundWorker1.RunWorkerAsync(arrayList);
 
   }
 
 
   void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
   {
      ArrayList newArrayList = (ArrayList) e.Argument;
      Console.WriteLine(ab[0].ToString());
            
      //In here there will be processing to deceide what should be placed in the textbox, but my question is
      //how do I get the value that I need in the textbox from the DoWork method to the RunWorkerCompleted callback?
     
      if (ab[0] == "happy")
         ab[0] = "not really";
      //Now that I've changed the arrayList, how do I pass it to the RunWorkerCompleted callback so that the string
      //can be placed in the textbox?
 
     
   }
 
   private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
   {
      //It is here that I have read that components need to be updated, but from the object sender and 
      //the RunWorkerCompletedEventArgs parameters, how do i get at the arrayList?
   }
 
 
}