Images not showing in excel using npoi - npoi

Question

The below code which uses npoi to create excel documents displays images in open office calc but not in excel.
If i open the doc in calc and save the document and then open the document in excel i can then see the images in excel.
Here is the code.
public static byte[] CreateExcel(CampaignViewModel viewModel, string fileName)
{
byte[] output;
using (FileStream fs = new FileStream(HttpContext.Current.Server.MapPath(#"\Data\templates\NPOITemplate.xls"), FileMode.Open, FileAccess.ReadWrite))
{
var templateWorkbook = new HSSFWorkbook(fs, true);
var sheet = templateWorkbook.GetSheet("Sheet1");
var patriarch = sheet.CreateDrawingPatriarch();
var leftFieldHeaders = CsvHelper.GetMatrixAllLeftFields();
var productHeaders = CsvHelper.GetMatrixProducts(viewModel.ProductCampaigns);
var totalCols = leftFieldHeaders.Count + productHeaders.Count;
var colWidth = 5000;
for (int i = 0; i < totalCols; i++)
{
sheet.SetColumnWidth(i, colWidth);
}
var imageRow = sheet.CreateRow(0);
imageRow.Height = 2000;
var imageCellCount = 0;
foreach (var header in leftFieldHeaders)
{
imageRow.CreateCell(imageCellCount).SetCellValue("");
imageCellCount++;
}
foreach (var product in viewModel.ProductCampaigns)
{
try
{
var anchor = new HSSFClientAnchor(0, 0, 0, 0, imageCellCount, 0, imageCellCount, 0);
anchor.AnchorType = 2;
var path = HttpContext.Current.Server.MapPath(product.Product.ImageThumbUrl);
var picture = patriarch.CreatePicture(anchor, LoadImage(#path, templateWorkbook));
picture.Resize();
picture.LineStyle = HSSFPicture.LINESTYLE_SOLID;
}
catch (Exception)
{
}
imageCellCount++;
}
using (MemoryStream ms = new MemoryStream())
{
templateWorkbook.Write(ms);
output = ms.ToArray();
}
}
return output;
}
public static int LoadImage(string path, HSSFWorkbook wb)
{
try
{
var file = new FileStream(path, FileMode.Open, FileAccess.ReadWrite);
var buffer = new byte[file.Length];
file.Read(buffer, 0, (int)file.Length);
return wb.AddPicture(buffer, PictureType.JPEG);
}
catch (Exception)
{
return 0;
}
}

Answer 1

i've resolved the above in a round about way. Turns out i didn't really need to use the template and could just create the xls from scratch. This add's a bit more meta data to the file which i suspect was the issue
public static byte[] CreateExcel2(CampaignViewModel viewModel, ICollection<DeliveryPoint> deliveryPoints, string fileName)
{
FileContentResult fileContentResult;
byte[] output;
var matrixCampaignLines = viewModel.MatrixCampaignLines;
HSSFWorkbook hssfworkbook = new HSSFWorkbook();
DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
dsi.Company = "NPOI Team";
hssfworkbook.DocumentSummaryInformation = dsi;
////create a entry of SummaryInformation
SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
si.Subject = "NPOI SDK Example";
hssfworkbook.SummaryInformation = si;
var sheet = hssfworkbook.CreateSheet("Sheet1");
var patriarch = sheet.CreateDrawingPatriarch();
var leftFieldHeaders = (viewModel.Campaign.EnableNameOnCampaign) ? CsvHelper.GetMatrixAllLeftFields() : CsvHelper.GetMatrixAllLeftFieldsWithoutName();
var productHeaders = CsvHelper.GetMatrixProducts(viewModel.ProductCampaigns);
var totalCols = leftFieldHeaders.Count + productHeaders.Count;
var colWidth = 5000;
for (int i = 0; i < totalCols; i++)
{
sheet.SetColumnWidth(i, colWidth);
}
var imageRow = sheet.CreateRow(0);
imageRow.Height = 2000;
var imageCellCount = 0;
foreach (var header in leftFieldHeaders)
{
imageRow.CreateCell(imageCellCount).SetCellValue("");
imageCellCount++;
}
foreach (var product in viewModel.ProductCampaigns)
{
try
{
var anchor = new HSSFClientAnchor(0, 0, 0, 0, imageCellCount, 0, imageCellCount, 0);
anchor.AnchorType = 2;
var path = HttpContext.Current.Server.MapPath(product.Product.ImageThumbUrl);
var picture = patriarch.CreatePicture(anchor, LoadImage(#path, hssfworkbook));
picture.Resize();//Comment this line if your code crashes.
picture.LineStyle = HSSFPicture.LINESTYLE_SOLID; might not
}
catch (Exception)
{
}
imageCellCount++;
}
using (MemoryStream ms = new MemoryStream())
{
hssfworkbook.Write(ms);
output = ms.ToArray();
}
return output;
}
public static int LoadImage(string path, HSSFWorkbook wb)
{
try
{
var file = new FileStream(path, FileMode.Open, FileAccess.Read);
var buffer = new byte[file.Length];
file.Read(buffer, 0, (int)file.Length);
return wb.AddPicture(buffer, PictureType.JPEG);
}
catch (Exception)
{
return 0;
}
}

Answer 2

I got it right now.
I am using
try
{
ISheet sheet = templateWorkbook.GetSheet(sheetName);
HSSFPatriarch patriarch = (HSSFPatriarch)sheet.CreateDrawingPatriarch();
//create the anchor
HSSFClientAnchor anchor;
anchor = new HSSFClientAnchor(0, 0, 255, 255,
start.Col, start.Row, end.Col, end.Row);
anchor.AnchorType = 2;
patriarch.CreatePicture(anchor,
LoadImage(imagePath, templateWorkbook));
}
catch (IOException ioe)
{
}
and LoadImage() method which returns path from the server.
Use this one. It runs fine.