Consider this code: procedure SplitAt(const _Input: string; _Position: integer; out _Head, _Tail: string); begin _Head := Copy(_Input, 1, _Position-1); _Tail := Copy(_Input, _Position); end; It's meant to split a given string into two parts at the given position. Nothing fancy, really, isn't it? Now, consider this call to the procedure above: var s1: string; s2: … Continue reading When const doesn’t mean const →

It just took me quite a while to find this information so I'll put it here for future reference. A Firemonkey application can not just access the clipboard, it needs to ask the platform whether it actually has one, then get the service interface and use that. uses Fmx.Platform; [...] function TryGetClipboardService(out _clp: IFMXClipboardService): boolean; … Continue reading Accessing the clipboard in a Firemonkey application →

I have just updated dzEditorLineEndsFix to address a small problem: The tool can be too fast so the file is already gone when Delphi tries to access it. It now waits 200 ms after detecting the file creation before moving it. This should solve the issue. It's available for download from the dzEditorLineEndsFix page on … Continue reading Updated dzEditorLineEndsFix →

Note to self: If MS Access adds double quotes to field names in queries, do not use them! It won't complain about them (You'd wish it would), but it just won't work. So if you see something like: SELECT * FROM t_Mst_Tageserfassung WHERE ("TeMitarbeiter"=92) AND ("TeArbeitstag"=#12/24/2014#); Remove the quotes and it will start to work … Continue reading Note to self: Do not use double quotes around field names →

Today I spent several hours hunting down a problem with opening a COM port. Basically the program opens a COM port, writes some bytes to it, reads an answer and closes it again. This determines whether the expected device is connected to the COM port or not. If the answer is the expected one, so … Continue reading When CloseHandle does not close the handle →

Once in a while I run into this problem and every single time it takes me forever to remember the cause: Say, you have got an interface and a class implementing that interface: type IMyInterface = interface function asMyInterface: IMyInterface; end; type TMyClass = class(TInterfacedObject, IMyInterface) private function asMyInterface: IMyInterface; end; [...] function TMyClass.asMyInterface: IMyInterface; … Continue reading class as interface: Operator not applicable to this operand →