Problem in exporting xlsx to pdf

Thanks for answering but I found my answer.
I should activate a arbitrary cell before exporting to pdf. because chart must be unselected.
before my code, I used this:

(myWorkSeet.Cells[1,1] as Excel.Range).Activate();

Hi Majid,

Please check if you are doing the same steps like below:

string paramSourceBookPath = @"C:\MyExcel.xlsx";
object paramMissing = Type.Missing;

string paramExportFilePath = @"C:\MyTestPdf.pdf";
XlFixedFormatType paramExportFormat = XlFixedFormatType.xlTypePDF;
XlFixedFormatQuality paramExportQuality =
XlFixedFormatQuality.xlQualityStandard;
bool paramOpenAfterPublish = false;
bool paramIncludeDocProps = true;
bool paramIgnorePrintAreas = true;
object paramFromPage = Type.Missing;
object paramToPage = Type.Missing;

try
{
// Open the source workbook.
excelWorkBook = excelApplication.Workbooks.Open(paramSourceBookPath,
paramMissing, paramMissing, paramMissing, paramMissing,
paramMissing, paramMissing, paramMissing, paramMissing,
paramMissing, paramMissing, paramMissing, paramMissing,
paramMissing, paramMissing);

// Save it in the target format.
if (excelWorkBook != null)
excelWorkBook.ExportAsFixedFormat(paramExportFormat,
paramExportFilePath, paramExportQuality,
paramIncludeDocProps, paramIgnorePrintAreas, paramFromPage,
paramToPage, paramOpenAfterPublish,
paramMissing);
}
catch (Exception ex)
{
// Respond to the error.
}
finally
{
// Close the workbook object.
if (excelWorkBook != null)
{
excelWorkBook.Close(false, paramMissing, paramMissing);
excelWorkBook = null;
}

// Quit Excel and release the ApplicationClass object.
if (excelApplication != null)
{
excelApplication.Quit();
excelApplication = null;
}

GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();
GC.WaitForPendingFinalizers();
}


Please do not forget to mark "Accepted Answer".

I saw articles on the right side about iTextSharp, but they are not useful for me.
I want to create a pdf from an existing excel file.
Also I do not have enough time to learn iTextSharp.

Please help.