Regarding Express Grid Control - Combobox inside Express Quantum Grid detail record

indenting ?

you free the query DBISAMQuery1,
but  ... don't create it in this procedure

gues you are getting access violation when entering this proc a second time ?

ewangoya: No,it did'nt worked when i try doing that no items are getting populated do i need to set the combo box property at the design time of the grid column.No it is set both design time and in run time as stated in your code.

Geert_Gruwez: Thanks,was getting access violation and now i commented it out the code in finally block.

ewangoya: oninitpopup event is not at all getting called when does this event will happen?my scenario is i have master record with 6 coulmns and under that detail records will be displayed with the expand and collapse functionality.Now the detail record 4 coulmn is set to combo box as the property ,now i want to pull up the data for every detail record based on the 4 th column in the master record.

Guess this depicts the overall scenario ? me tried out writing in getproperties and getpropertiesedit event but no luck .could you please assist me on this because i am new to express quantum grid control.

Thanks in advance.

Sorry, I missed the expand part of your question, I'll look into it in a while

can you post a screenshot of what you are trying to do

combobox and detail below the row is 2 completely different things

Ok,

first thing, how did you set up the OnInitPopup event.
This event will be called any time you click on a combobox. You set it up from the Object Inspector

second, you cant do this
PrintLocation := GetPrintLocation(cxGrid1DBTableView1.DataController.GetDisplayText(cxGrid1DBTableView1Column3.DataBinding.DataController.FocusedRecordIndex,1));
Just because a row is expanded does not mean the master view is at the correct parent record

third, I'm not sure why you have this code, if the field is not yet bound at this time, nothing will work in this piece of code
cxGrid1DBTableView2NEWMETHOD.DataBinding.FieldName := 'NEW METHOD';

fourth, use the Sender instance instead of typecasting the column
TcxComboBoxProperties(cxGrid1DBTableView2NEWMETHOD.Properties)

I'll try and fix your code in a few minutes

Here, this should work so  long as your table has the requested data and you set up the OnInitPopup event properly

Note: Your method of reopening the query everytime is very inefficient it terms of speed, You should store the data in a memory dataset and when requested, just filter the records you want

procedure TForm3.cxGrid1DBTableView2NEWMETHODPropertiesInitPopup(Sender: TObject);
const
  C_Query_New = 'select NewMethod from "C:\RAPID\RPFILES\PrintLocation.db4" where PrintLocationName = ''%0:s''';
var
  PrintLocation : string;
  ComboBox: TcxCustomComboBoxProperties;
  GridRecord: TcxCustomGridRecord;
begin
  ComboBox := (Sender as TcxCustomComboBox).Properties as TcxCustomComboBoxProperties;
  ComboBox.Items.Clear;

  GridRecord := cxGrid1DBTableView1.MasterGridRecord;
  PrintLocation := GetPrintLocation(GridRecord.Values[cxGrid1DBTableView1Column3.Index]);
  if PrintLocation = '' then
    Exit;

  DBISAMQuery1.Close;
  try
    DBISAMQuery1.SQL.Clear;
    DBISAMQuery1.SQL.Add(Format(C_Query_New, [PrintLocation]));
    //DBISAMQuery1.ExecSQL; execsql is used for statements that dont return a resultset
    DBISAMQuery1.Open;
    while not DBISAMQuery1.Eof do
    begin
      ComboBox.Items.Add(DBISAMQuery1.FieldByName('NewMethod').AsString);
      DBISAMQuery1.Next;
    end;
  finally
    DBISAMQuery1.Close;
    DBISAMQuery1.SQL.Clear;
  end;
end;

Select allOpen in new window

SelectInitPopup.png

Disregard the method I showed you using OnInitPopup. I tested that and it will be extremely slow since you have to reload everytime the combobox is pressed. A much better way is to use the DetailExpand event. This is called only once when the child tab is expanded

So this here is a better solution

procedure TForm3.cxGrid1DBTableView1DataControllerDetailExpanded(
  ADataController: TcxCustomDataController; ARecordIndex: Integer);
const
  C_Query_New = 'select NewMethod from "C:\RAPID\RPFILES\PrintLocation.db4" where PrintLocationName = ''%0:s''';
var
  PrintLocation : string;
  ComboBox: TcxCustomComboBoxProperties;
begin
  ComboBox := cxGrid1DBTableView2NEWMETHOD.Properties as TcxCustomComboBoxProperties;
  ComboBox.Items.Clear;

  //You can check if the value is null first
  PrintLocation := ADataController.Values[ARecordIndex, cxGrid1DBTableView1Column3.Index];
  PrintLocation := GetPrintLocation(PrintLocation);
  if PrintLocation = '' then
    Exit;
      
  DBISAMQuery1.Close;
  try
    DBISAMQuery1.SQL.Clear;
    DBISAMQuery1.SQL.Add(Format(C_Query_New, [PrintLocation]));
    //DBISAMQuery1.ExecSQL; execsql is used for statements that dont return a resultset
    DBISAMQuery1.Open;
    while not DBISAMQuery1.Eof do
    begin
      ComboBox.Items.Add(DBISAMQuery1.FieldByName('NewMethod').AsString);
      DBISAMQuery1.Next;
    end;
  finally
    DBISAMQuery1.Close;
    DBISAMQuery1.SQL.Clear;
  end; 
end;

Select allOpen in new window

Here is a simple example
Unit3.dfm
Unit3.pas

Thanx much needed one,task accomplished