Application.Wait or Thread.Sleep

Question

I am already using backgroundworker.RunAsyn() to run my code on a separate thread. However I am hitting a portion where the code iterates to the next line before the previous line is completed. Should I create a separate backgroundworker to handle that? Or should I use Application.Wait() or Thread.Sleep() I am not sure the amount of time to delay and I'd rather not have my program just sitting around waiting for extra un-needed time so I am not sure which route to take. Here is a snippet of the trouble-maker.

public Form_Main()
{
   InitializeComponent();
   backgroundworker1.WorkerReportsProgress = true;
   backgroundworker1.DoWork += new DoWorkEventHandler(backgroundWorker1_DoWork);
   backgroundWorker1_ProgressChanged += new ProgressChangedEventHandler(backgroundWorker1_ProgressChanged);
}

private void btnOpenRefreshSave_Click()
{
   backgroundWorker1_RunWorkerAsync();
}

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
   Excel.Application exApp;
   Excel._Workbook exBook;
   Excel._Worksheet exSheet;

   exBook = (Excel._Workbook)(exApp.WOrkbooks.Open("C:\\Book1.xlsx")); 
   exSheet = (Excel._Worksheet)(exBook.ActiveSheet);
   //This is the line of code that often times takes a while
   exBook.RefreshAll();
   //end of trouble line
   exBook.SaveAs("C:\\Updated_Book1.xlsx");
}

private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{

}

Answer 1

A few things come to mind on what to do here. You could try using something similar to the below

if (Application.CalculationState === xlDone Then
    everything is finished calculating[enter link description here][1]

Another option would be (as others have suggested) changing the background refresh property. A quick scan of the workbooks could programmatically change that for you

foreach (Wrksheet ws in workbook.wss)
{
    foreach (QueryTable table in ws.QueryTables)
      table.BackgroundQuery = false;
}
workbook.RefreshAll();