Datatable转Excel

public static void ExportToExcel( DataTable tbl, string excelFilePath = null)
{
try
{
if (tbl == null || tbl.Columns.Count == 0)
throw new Exception("ExportToExcel: Null or empty input table!
");

// load excel, and create a new workbook
var excelApp = new Excel.Application();
excelApp.Workbooks.Add();

// single worksheet
Excel._Worksheet workSheet = excelApp.ActiveSheet;

// column headings
for (var i = 0; i < tbl.Columns.Count; i++)
{
workSheet.Cells[1, i + 1] = tbl.Columns[i].ColumnName;
}

// rows
for (var i = 0; i < tbl.Rows.Count; i++)
{
// to do: format datetime values before printing
for (var j = 0; j < tbl.Columns.Count; j++)
{
workSheet.Cells[i + 2, j + 1] = tbl.Rows[i][j];
}
}

// check file path
if (!string.IsNullOrEmpty(excelFilePath))
{
try
{
workSheet.SaveAs(excelFilePath);
excelApp.Quit();
Console.WriteLine("Excel file saved!");
}
catch (Exception ex)
{
throw new Exception("ExportToExcel: Excel file could not be saved! Check filepath.
"
+ ex.Message);
}
}
else
{ // no file path is given
excelApp.Visible = true;
}
}
catch (Exception ex)
{
throw new Exception("ExportToExcel: 
" + ex.Message);
}
}