On Wed, 25 May 2016, Graeme Geldenhuys wrote:
Hi, Can I safely assign a method from an Interface reference to an event handler. The code below works, but I'm not sure if it is safe to do so, and allowed. ================================== TTestApp = class(TObject) private rpt: TFPReportReport; FReportFilter: IFPReportFilter; // can hold any export filter ... constructor TTestApp.Create; begin rpt := TFPReportReport.Create(nil); rpt.Author := 'Graeme Geldenhuys'; rpt.Title := 'FPReport Demo 4 - Frames and Fonts'; FReportFilter := TFPReportExportPDF.Create; // PDF output //FReportFilter := TFPReportExportAggPas.Create; // PNG output rpt.OnRenderReport := @FReportFilter.RenderReport; ... end;
I am not sure this is safe to do, since an event handler exists of 2 pointers: data and method. As far as I know, an interface does not have a data pointer. Michael. _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
