TFieldGetData (Delphi)

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Description

This example requires a button, a test edit, and a populated ClientDataSet. Pipe the ClientDataSet through a DataSource to a DGGrid or DBNavigator to control the current field. Cast the data correctly according to the field type when assigning to the test edit.

Code

{$IFNDEF UNICODE}
uses SwSystem;
{$ENDIF}

procedure TForm1.Button1Click(Sender: TObject);
var MyBuffer: Pointer;
begin
{ Retrieve the "raw" data from Field1. }
with CDS.Fields[0] do
  begin
    if not IsBlob then { This does not work for BLOB fields. }
    begin
      { Allocate space. }
      MyBuffer:= GetMemory(DataSize);
      try
        if not GetData(MyBuffer) then
          MessageDlg(DisplayName + ' is NULL', mtInformation, [mbOK], 0)
        else
          { Do something with the data. };
          Edit1.Text:= string(PAnsiChar(MyBuffer)); // For a stringfield
      finally
        { Free the space. }
        FreeMem(MyBuffer, DataSize);
      end;
    end;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
{$IFDEF UNICODE}
  CDS.LoadFromFile(GetCurrentDir + '\CDS.XML');
{$ELSE}
  CDS.LoadFromFile(gsAppPath + 'CDS.XML');
{$ENDIF}
end;

Uses

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