public static double RowsUsedHeight(this ExcelWorksheet ws)
{
double h = 0;
for (var i = 1; i <= ws.RowCount(); i++)
{
h += ws.Row(i).Height;
}
return(h);
}
public static ExcelRange UsedRange(this ExcelWorksheet ws) => ws.Cells[1, 1, ws.RowCount(), ws.ColumnCount()];