NPOI - Get excel row count to check if it is empty

Question

I'm reading an xlsx file using NPOI lib, with C#. I need to extract some of the excel columns and save the extracted values into some kind of data structure.

I can successfully read the file and get all the values from the 2nd (the first one contains only headers) to the last row with the following code:

...
workbook = new XSSFWorkbook(fs);
sheet = (XSSFSheet)workbook.GetSheetAt(0);
....
int rowIndex = 1;  //--- SKIP FIRST ROW (index == 0) AS IT CONTAINS TEXT HEADERS
while (sheet.GetRow(rowIndex) != null) {
    for (int i = 0; i < this.columns.Count; i++){
       int colIndex = this.columns[i].colIndex;
       ICell cell = sheet.GetRow(rowIndex).GetCell(colIndex);
       cell.SetCellType(CellType.String);
       String cellValue = cell.StringCellValue;
       this.columns[i].values.Add(cellValue); //--- Here I'm adding the value to a custom data structure
    }
    rowIndex++;
}

What I'd like to do now is check if the excel file is empty or if it has only 1 row in order to properly handle the issue and display a message

If I run my code against an excel file with only 1 row (headers), it breaks on

cell.SetCellType(CellType.String); //--- here cell is null

with the following error:

Object reference not set to an instance of an object.

I also tried to get the row count with

sheet.LastRowNum

but it does not return the right number of rows. For example, I have created an excel with 5 rows (1xHEADER + 4xDATA), the code reads successfully the excel values. On the same excel I have removed the 4 data rows and then I have launched again the code on the excel file. sheet.LastRowNum keeps returning 4 as result instead of 1.... I think this is related to some property bound to the manually-cleaned sheet cells.

Do you have any hint to solve this issue?

Answer 1

I think it would be wise to use sheet.LastRowNum which should return the amount of rows on the current sheet

Answer 2

Am I oversimplifying?

 bool hasContent = false;

 while (sheet.GetRow(rowIndex) != null)
        {
            var row = rows.Current as XSSFRow;
            //all cells are empty, so is a 'blank row'
            if (row.Cells.All(d => d.CellType == CellType.Blank)) continue;  


            hasContent = true;
        }