以电子邮件附件形式发送pdf

我当前的应用程序在附件中发送一个.rtf。我想发送pdf而不是那个。 在我的代码中,我应该在哪里修改相同的代码?

下面是我的代码

        RichTextBox rtbReport = new RichTextBox();   //Creating instance of Richtextbox
        AppResult objResult = null;                  //Object of Class
        frmExaminationReport objReport = new frmExaminationReport(examinationID,   ProviderID, PatientID, examType);                        // Object of Class
        AddressBookDataTable dtAddress = null;
        rtbReport.Rtf = objReport.RTF;               // Entire Result is assigned to Richtext box class
         frmMail objMail = new frmMail();            //Object of Mail Class
         string directoryPath = Application.StartupPath + "\\Temp"; //Creating directory

         string tempFileName = "Report_" + DateTime.Today.Year.ToString() +  DateTime.Today.Month.ToString() + ".rtf";      //Generating Name
            FileStream fsReport = new FileStream(directoryPath + "\\" + tempFileName, FileMode.CreateNew);                            // FileStream
            fsReport.Write(ASCIIEncoding.ASCII.GetBytes(rtbReport.Rtf), 0, rtbReport.Rtf.Length);                         // Writing
            fsReport.Flush();
            fsReport.Close();
            fsReport.Dispose();
            objMail.MailSubject = examType + " Report";   //Mail Subject

如果需要任何输入,请告诉我