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#65: How can I save/restore the component into BLOB-field?

Sometimes in applications you must save the component into BLOB-field of the own table and in run-time to restore it. For example, to save the report form and in run-time the end-user will select the wished report before report generation.

The next two procedure allows to save the component with all properties and restore it.

procedure SaveCompToBlob(AField: TBlobField; AComponent: TComponent);
var
  Stream: TBlobStream;
  CompName: string;
begin
  CompName := Copy(AComponent.ClassName, 2, 99);
  Stream := TBlobStream.Create(AField, bmWrite);
  try
    Stream.WriteComponentRes(CompName, AComponent);
  finally
    Stream.Free;
  end;
end;

procedure LoadCompFromBlob(AField: TBlobField; AComponent: TComponent);
var
  Stream: TBlobStream;
  i: integer;
begin
  try
    Stream := TBlobStream.Create(AField, bmRead);
    try
      {delete the all child components}
      for i := AComponent.ComponentCount - 1 downto 0 do
        AComponent.Components[i].Free;
      Stream.ReadComponentRes(AComponent);
    finally
      Stream.Free;
    end;
  except
    on EFOpenError do {nothing};
  end;
end;

Published: February 11, 2000

See also

	ExcelFile Viewer
	SMImport suite
	MAPIMail
	Paradox to MS Access converter
	DBISAM Viewer
	Database Information Manager
	Excel Reader (dll)
	DBExport tools
	ABA Document Convert
	Clarion to Text converter

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