Reading an Excel file and Generating a new excel file with additional information

// you have to download GemBox.Spreadsheet.dll
using GemBox.Spreadsheet;


ExcelFile ef = null;
ef.LoadXls(_filePath);
//for get text
string[] array = new string[ef.Worksheets.Count];
int i = 0;
foreach (ExcelWorksheet ws in ef.Worksheets)
{
array[i] = ws.Name;
i++;
}

string text = "";

for (int j = 0; j < i; j++)
{
ExcelWorksheet sheet = ef.Worksheets[array[j]];

foreach (ExcelRow er in sheet.Rows)
{
foreach (ExcelCell ec in er.Cells)
{
if (ec.Value != null)
text += ec.Value.ToString() + " ";

}
text += "\n";
}
text += "\n\n";
}
//for Get Rich Text
string text = "";

for (int j = 0; j < i; j++)
{
ExcelWorksheet sheet = ef.Worksheets[array[j]];

foreach (ExcelRow er in sheet.Rows)
{
foreach (ExcelCell ec in er.Cells)
{
if (ec.Value != null)
{
text += ec.Value.ToString() + "\n(";
text += ec.Style.Font.Name + "," + ec.Style.Font.Color.ToString() + ")\n";
}

}
text += "\n\n";
}
text += "\n\n\n";
}