I am using TcxExtLookupComboBox from Devexpress and am trying to implement my own data source. I installed customdatasource as follows:
procedure TMainForm.FormCreate(Sender: TObject);
begin
fDataSource := TMyDataSource.Create;
cbotestSearch.Properties.View.DataController.CustomDataSource := fDataSource;
end;
Here is the TMyDataSource:
unit Datasource;
interface
uses
Classes,
IBQuery,
SysUtils,
cxCustomData;
type
TSearchItem = class
private
BoldID: String;
Display: String
end;
TMyDataSource = class(TcxCustomDataSource)
private
fSearchList: TList;
protected
function GetRecordCount: Integer; override;
function GetValue(ARecordHandle: TcxDataRecordHandle; AItemHandle: TcxDataItemHandle): Variant; override;
public
constructor Create;
destructor Destroy; override;
procedure GetData;
end;
implementation
constructor TMyDataSource.Create;
begin
inherited Create;
fSearchList := TList.Create;
end;
destructor TMyDataSource.Destroy;
begin
FreeAndNil(fSearchList);
inherited;
end;
procedure TMyDataSource.GetData;
var
vItem: TSearchItem;
begin
fSearchList.Clear;
vItem := TSearchItem.Create;
vItem.BoldID := '1000';
vItem.Display := 'test';
fSearchList.Add(vItem);
vItem := TSearchItem.Create;
vItem.BoldID := '1100';
vItem.Display := 'test2';
fSearchList.Add(vItem);
DataChanged; // Don't do anything as provider is nil
end;
function TMyDataSource.GetRecordCount: Integer;
begin
// Is never entered
Result := fSearchList.Count;
end;
function TMyDataSource.GetValue(ARecordHandle: TcxDataRecordHandle;
AItemHandle: TcxDataItemHandle): Variant;
begin
// Is never entered
Result := 'Test';
end;
end.
The problem is that TMyDataSource.GetValue is never called. Any hint how to fix?
Update 1: I have one more hint. If I have one step in the DataChanged method that should call GetValue, it looks like this:
procedure TcxCustomDataSource.DataChanged;
begin
if Provider = nil then Exit;
// Code using Provider
end;
and the provider in this case is zero. But I assigned a Datasource to Forms oncreate, as you can see.
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