tt

public static byte[] ConvertDataTableToExcelBuffer(DataTable table)
{
ExcelPackage.LicenseContext = LicenseContext.NonCommercial;
byte[] result = null;
using (var ms = new MemoryStream())
{
using (ExcelPackage package = new ExcelPackage(ms))
{
// add a new worksheet to the empty workbook
ExcelWorksheet worksheet = package.Workbook.Worksheets.Add("Documents");
//First add the headers
int colIndex = 1;
foreach (DataColumn prop in table.Columns)
{
worksheet.Cells[1, colIndex].Value = prop.ColumnName;
colIndex++;
}


var row = 2;
foreach (DataRow doc in table.Rows)
{
colIndex = 1;
foreach (DataColumn prop in table.Columns)
{
var value = doc[prop.ColumnName];
if (value != null)
{
value = value.ToString().Replace("<br>", "");
}
worksheet.Cells[$"{GetExcelColumnName(colIndex)}{row}"].Value = value;
colIndex++;
}
row++;
}
package.Save(); //Save the workbook.
ms.Position = 0;
//var contentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
//var fileName = $"doc_exp_{DateTime.Now.ToString("yyyy-MM-dd_HH-mm-ss")}.xlsx";

}
result = ms.ToArray();
}

 

return result;
}

　　

var filebyte = ExcelHelper.ConvertToExcelBuffer(ds);
var fname = $"{t}-{DateTime.Now.ToString("yyyyMMddHHmmss")}";
return this.File(filebyte, "application/octet-stream", fname + ".xlsx");

private static string GetExcelColumnName(int columnNumber)
{
int dividend = columnNumber;
string columnName = String.Empty;
int modulo;

while (dividend > 0)
{
modulo = (dividend - 1) % 26;
columnName = Convert.ToChar(65 + modulo).ToString() + columnName;
dividend = (int)((dividend - modulo) / 26);
}

return columnName;
}