How to show a row number value in an unbound Grid column

Description:
I want to give the user to see a collumn showing the number of the row, like a ranking. How can I do this?

Answer:
This feature can be implemented using the OnGetDisplayText event of a column. Basically, you need to know the Index of a row painted and show it in a cell. Here is some sample code:

Delphi
procedure ColumnGetDisplayText(  
  Sender: TcxCustomGridTableItem; ARecord: TcxCustomGridRecord;  
  var AText: String);  
var  
  Row: Integer;  
begin  
  Row := Sender.GridView.DataController.GetRowIndexByRecordIndex(ARecord.RecordIndex, False);  
  AText := IntToStr(Row);  
end;  

However, this approach does not work when Grid is in grid mode, because in this mode, the data controller loads a fixed number of dataset records into memory. So, the ARecord.RecordIndex property does not return an actual record index. In this case, you can use the DataSet.RecNo property to calculate row index for the Grid records:

Delphi
procedure ColumnGetDisplayText(  
  Sender: TcxCustomGridTableItem; ARecord: TcxCustomGridRecord;  
  var AText: string);  
var  
  AFocusedRecordIndex, ARecno: Integer;  
begin  
  ARecno := TcxGridDBTableView(Sender.GridView).DataController.DataSource.DataSet.RecNo;  
  AFocusedRecordIndex :=  TcxGridDBTableView(Sender.GridView).Controller.FocusedRecordIndex;  
  AText := IntToStr( ARecno - AFocusedRecordIndex + ARecord.Index);  
end;  

See also:
A95: How to display an image from a data table in an Unbound View
A1095: How to set up an unbound item in a data-aware View