Though not new to .Net development, I am new to programming against the Office object model, so this may be a simple question. However, it's driving me crazy, so thanks again for your help.

I have an Excel file that I need to load into the object model and process it through a command processing engine that we have written. I had initially tried to accomplish this via the OleDb driver for Excel, but because the data must be written back to the Excel file (which has ~300 columns and +2000 rows) and because formatting must be preserved, I am having to use the Office PIA method. Therefore, after looking into how Excel uses Ranges for virtually everything, I wrote a small test function to iterate through my worksheet and write out the first column -- unfortunately, this does not work and I'm at my wits end trying to figure out what I'm doing wrong. The code is posted below -- thanks.

_howard

ApplicationClass app = new Microsoft.Office.Interop.Excel.ApplicationClass();
app.Visible = true;
_Workbook wbook = app.Workbooks.Open(this.txtExcelFile.Text, 0, false, 5, string.Empty,
string.Empty, true, XlPlatform.xlWindows, string.Empty, false, false, 0, true, false,
false);
try
{
//get first worksheet
Sheets sheets = wbook.Sheets;
Worksheet firstSheet = (Worksheet)wbook.ActiveSheet;

Range rngUsed = firstSheet.UsedRange;

//write total number of rows and cols
Debug.WriteLine("Rows: " + rngUsed.Rows.Count.ToString());
Debug.WriteLine("Cols: " + rngUsed.Columns.Count.ToString());

foreach(Range currentRow in rngUsed.Rows) //FAILS HERE!!!
{
Debug.WriteLine(((Range)currentRow[1,1]).Value2.ToString());
}