C# - MS Word - MailMerge how to get Last Record when MailMerge.DataSource.LastRecord returns -16

Question

Unable to get Last record using MailMerge.DataSource.LastRecord or MailMerge.DataSource.RecordCount the first variable always returns -16 and the second one returns -1.

Answer 1

Cause:
.LastRacord and .RecordCount was returning -16 and -1 because I was reading data from the CSV file.

Solution: The following code will return the last record or record count reading dataset from CSV file or text file.

public int GetMailMergeLastRecord()
 {
       Document doc = Globals.AddIn.ActiveDocument;      
       // for storing current record
       int currentRec = (int)doc.Mailmerge.DataSource.ActiveRecord;

       //getting the last Record
       int lastRecord = 1;
       doc.MailMerge.DataSource.ActiveRecord = (doc.MailMerge.DataSource.ActiveRecord - (int)doc.MailMerge.DataSource.ActiveRecord) + Int32.MaxValue;
       lastRecord =  (int)doc.MailMerge.DataSource.ActiveRecord;

       // resetting the current record as above line of codes will change the active record to last record.
       doc.MailMerge.DataSource.ActiveRecord = (doc.MailMerge.DataSource.ActiveRecord - (int)doc.MailMerge.DataSource.ActiveRecord) + currentRec;
       return lastRecord;
}

Note
The above code is for word application level AddIn