using c# to select a worksheet in excel

Question

Using C# in .NET 3.5 with Visual Studio 2008, I am trying to set focus (or activate) a specific worksheet in an open workbook:

Here are some properties:

public Excel.Application xlApp {get;set;}
public Excel.Workbook xlWorkBook { get; set; }
public Excel.Worksheet xlWorkSheet { get; set; }
public Excel.Range range { get; set; }        

And here is how I am trying to select a specific worksheet:

(xlWorkSheet)Application.ActiveWorkbook.Sheets[FormControls.WorksheetFocus]).Select(Type.Missing);

And I have also tried this way:

((Excel.Worksheet)this.Application.ActiveWorkbook.Sheets[1]).Select();

What am I doing wrong? How do I select a specific worksheet in a workbook using C#?

---

explanation of where the definitions are:

namespace EmailSalesVolumeSolution
{
    class WorkBook
    {
        public string MasterFileName { get; set; }
        public string[] DistinctEmails { get; set; }
        public Excel.Application xlApp {get;set;}
        public Excel.Workbook xlWorkBook { get; set; }
        public Excel.Worksheet xlWorkSheet { get; set; }
        public Excel.Range range { get; set; }    

and everything is in the same class and namespace

here is how it is initiliazed:

private void OpenWorkBook()
{
    string str;
    int rCnt = 0;
    int cCnt = 0;


    xlApp = new Excel.ApplicationClass();
    xlWorkBook = xlApp.Workbooks.Open(MasterFileName, 0, true, 5, "", "", true,
        Microsoft.Office.Interop.Excel.XlPlatform.xlWindows,
        "\t", false, false, 0, true, 1, 0);
    xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(FormControls.WorksheetEmails);

Answer 1

Here is what I did and it works!

Excel.Worksheet xlWorkSheetFocus = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(2);
xlWorkSheetFocus.Activate();