Based on the answer from Duc Tran Minh, it works fine for me after I modified the code like this:
static void Main(string[] args)
{
ExcelPackage p = new ExcelPackage(new System.IO.FileInfo("X.XLSX"));
var sheet = p.Workbook.Worksheets["HMTD"];
var noOfCol = sheet.Dimension.End.Column;
var noOfRow = sheet.Dimension.End.Row;
StringBuilder s = new StringBuilder();
s.Append("<table>");
for (int i = 1; i <= noOfRow; i++)
{
s.Append("<tr>");
for (int j = 1; j <= noOfCol; j++)
{
int colspan = 1;
int rowspan = 1;
if (!sheet.Cells[i, j].Merge || (sheet.Cells[i, j].Merge && isFirstMergeRange(sheet, sheet.Cells[i, j].Address, ref colspan, ref rowspan)))
{
s.Append("<td rowspan='" + rowspan + "' colspan='" + colspan + "'>");
if(sheet.Cells[i,j] != null && sheet.Cells[i,j].Value != null)
s.Append(sheet.Cells[i,j].Value.ToString());
s.Append("</td>");
}
}
s.Append("</tr>");
}
s.Append("</table>");
System.IO.File.WriteAllText("duc.html",s.ToString());
Console.ReadKey();
}
bool isFirstMergeRange(ExcelWorksheet sheet, string address, ref int colspan, ref int rowspan)
{
colspan = 1;
rowspan = 1;
foreach (var item in sheet.MergedCells)
{
var s = item.Split(':');
if (s.Length > 0 && s[0].Equals(address))
{
ExcelRange range = sheet.Cells[item];
colspan = range.End.Column - range.Start.Column + 1;
rowspan = range.End.Row - range.Start.Row + 1;
return true;
}
}
return false;
}