TTMSFNCDataGridDatabaseAdapter.LoadMode Property

Controls how many records are buffered and who sorts, filters, and groups. Default is almBuffered.

API unit family: TMSFNCDataGridDatabaseAdapter Declaring type: TTMSFNCDataGridDatabaseAdapter Inherited from: TTMSFNCCustomDataGridDatabaseAdapter Type: TTMSFNCDataGridDatabaseAdapterLoadMode

Syntax

FMX.TMSFNCDataGridDatabaseAdapter.hppPascalC++

property LoadMode: TTMSFNCDataGridDatabaseAdapterLoadMode;

__property TTMSFNCDataGridDatabaseAdapterLoadMode LoadMode = {read=FLoadMode, write=SetLoadMode, default=0};

Default: almBuffered

Remarks

almBuffered buffers only the records of the visible rows (or the current page when paging is on), which suits large datasets. Sorting is passed to the dataset: an index on the first sorted column is created for client datasets, FireDAC datasets, and the product's own custom dataset, while other datasets need OnSortData. Filtering is translated into TDataSet.Filter. Grouping is not available.

almAllRecords buffers every record so the grid sorts, filters, and groups the data itself; filtering is still passed to the dataset when DetailControl is used.

Changing the value reloads the grid.

Usage examples

Combine buffered loading, field conversion, and display overrides

Configure a database adapter for a large dataset while formatting stored values and overriding the rendered text per cell.

Combine buffered loading, field conversion, and display overridesPascalC++

procedure TForm1.FormCreate(Sender: TObject);
begin
  Adapter.DataGrid := Grid;
  Adapter.DataSource := DataSource1;
  Adapter.AutoCreateColumns := True;
  Adapter.LoadMode := almBuffered;
  Adapter.DynamicRecordCount := True;
  Adapter.OnFieldToData := AdapterFieldToData;

  Grid.OnGetCellDisplayValue := GridGetCellDisplayValue;

  FDQuery1.Active := True;
end;

procedure TForm1.AdapterFieldToData(Sender: TObject;
  ACell: TTMSFNCDataGridCellCoord; AMasterField, AField: TField;
  var ACellValue: TTMSFNCDataGridCellValue; var Handled: Boolean);
begin
  if AField.FieldName = 'Amount' then
  begin
    ACellValue := FormatCurr('#,##0.00', AField.AsCurrency);
    Handled := True;
  end;
end;

procedure TForm1.GridGetCellDisplayValue(Sender: TObject;
  ACell: TTMSFNCDataGridCellCoord; AData: TTMSFNCDataGridCellValue;
  var AValue: string);
begin
  if (ACell.Row > 0) and (ACell.Column = StatusColumn) then
    AValue := '<b>' + AValue + '</b>';
end;

void __fastcall TForm1::FormCreate(TObject *Sender)
{
  Grid->Adapter = Adapter;  // the adapter is attached from the grid side
  Adapter->DataSource = DataSource1;
  Adapter->AutoCreateColumns = true;
  Adapter->LoadMode = almBuffered;
  Adapter->DynamicRecordCount = true;
  Adapter->OnFieldToData = AdapterFieldToData;

  Grid->OnGetCellDisplayValue = GridGetCellDisplayValue;

  FDQuery1->Active = true;
}

void __fastcall TForm1::AdapterFieldToData(TObject *Sender,
  const TTMSFNCDataGridCellCoord &ACell, TField *AMasterField, TField *AField,
  TTMSFNCDataGridCellValue &ACellValue, bool &Handled)
{
  if (AField->FieldName == "Amount")
  {
    ACellValue = TValue::From<System::UnicodeString>(FormatCurr("#,##0.00", AField->AsCurrency));
    Handled = true;
  }
}

void __fastcall TForm1::GridGetCellDisplayValue(TObject *Sender,
  const TTMSFNCDataGridCellCoord &ACell, const TTMSFNCDataGridCellValue &AData,
  System::UnicodeString &AValue)
{
  TTMSFNCDataGridCellCoord Cell = ACell;  // ACell is const; its getters are not
  if ((Cell.Row > 0) && (Cell.Column == StatusColumn))
    AValue = "<b>" + AValue + "</b>";
}

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