Question

I’m using GemBox to read Excel files. I’m copying the fields to a DataTable, so I have to add the columns to the DataTable first.

Therefore I’m using this code:

For i As Integer = 0 To objWorksheet.Columns.Count - 1
    objDataTable.Columns.Add(i, GetType(ExcelCell))
Next

But objWorksheet.Columns.Count is 0 even if there is data in 4 columns.

Any ideas?

Answer 1

Cells are internally allocated in rows and not in columns. ExcelColumn objects are created only if they have non-standard width or style, or they are accessed directly. So, while ExcelRowCollection.Count shows number of rows occupied with data, ExcelColumnCollection.Count does not say which Column is the last one occupied with data!

If you want to read all data in a sheet, use ExcelRow.AllocatedCells property.

If you want to find last column occupied with data, use CalculateMaxUsedColumns method.

In version 3.5 method ExcelWorksheet.CreateDataTable(ColumnTypeResolution) is added. This method will automatically generate DataTable columns with appropriate type from excel file columns and will import cells with data to DataTable rows.