Missy Missy - 2 months ago 10
C# Question

Excel Returns Null After Line 144 using C# Microsoft Interop Excel

In C#, I've opened an Excel spreadsheet and I am iterating through it. Whenever I get to line 144, the spreadsheet value returns null for every single line following it. Looking at the spreadsheet, it is clearly not null for lines 144 - 250. I tried saving it in different versions but that didn't work. I've tried copying and pasting into a brand new worksheet. Nothing has worked. Here is my code:

// initiate Excel
Excel.Application xlApp;
Excel.Workbook xlWorkBook;
Excel.Worksheet xlWorkSheet;
object misValue = System.Reflection.Missing.Value;

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

//Get the used Range
Excel.Range usedRange = xlWorkSheet.UsedRange;

//Iterate the rows in the used range
string customerNumber;
string amount;
int i = 0;
decimal dAmount = 0;

bool runProcess = true;
bool hasHeader = false;
string cellValue;
foreach (Excel.Range row in usedRange.Rows)
{
i++;
// Column 1 is customer number
// THE FOLLOWING LINE RETURNS NULL STARTING AT ROW 144
cellValue = row.Cells[i, 1].Value2 == null ? "" : row.Cells[i, 1].Value2.ToString();
if (!(cellValue.Length >= 5 && cellValue.Length <= 20))
{
MessageBox.Show(cellValue + " Must be between 5 and 20 Characters - File Will Not Be Processed Row#" + i.ToString());
runProcess = false;
}

}
// run process
// release EXCEL


I did try row.Cells[i, 1].Value2, row.Cells[i, 1].Value and row.Cells[i, 1].Text and got the same results for all. I am including "using Excel = Microsoft.Office.Interop.Excel;"

Sample Data from Excel

4492605768531895 15.95
4492605768536544 19.95
4492605768565459 11.95
4492605739542347 14.95
4492605768635795 25.95

Answer

I think it has something to do with the Range object size. I tried replace the foreach to this and it worked (for me the null was occurring in line 102)

int maxRows = usedRange.Rows.Count;
for (int i=1;i<=maxRows;i++)
{
    // Column 1 is customer number
   // THE FOLLOWING LINE RETURNS NULL STARTING AT ROW 144
   cellValue = xlWorkSheet.Cells[i, 1].Value2 == null ? "" : xlWorkSheet.Cells[i, 1].Value2.ToString();

    if (!(cellValue.Length >= 5 && cellValue.Length <= 20))
    {
        MessageBox.Show(cellValue + " Must be between 5 and 20 Characters - File Will Not Be Processed Row#" + i.ToString());
        runProcess = false;
    }

}