RTTI in Delphi is still not quite as full-featured as Reflection in .NET or other managed languages, because it is operating on compiled code, not an Intermediate Language (bytecode). However, it is a very similar concept, and the new RTTI system in Delphi 2010 brings it a lot closer to reflection, exposing an entire object-oriented … Read more
As ever so often Zarco Gajic has a solution: Capture the output from a DOS (command/console) Window. This is a copy from his article for future reference: The example runs ‘chkdsk.exe c:\’ and displays the output to Memo1. Put a TMemo (Memo1) and a TButton (Button1) on your form. Put this code in the OnCLick … Read more
As far as C goes they both do the same thing. It is a matter of preference. int* i shows clearly that it is an int pointer type. int *i shows the fact that the asterisk only affects a single variable. So int *i, j and int* i, j would both create i as an … Read more
To summarize, the problem happens only with published interface properties that have a getter method, and the property points to component on another form/module (and that form/module is not recreated yet). In such case restoring form DFM causes an AV. I’m pretty sure the bug is in the ASM code in GetOrdProp, but it’s beyond … Read more
I tried your code, it takes 00:10:439 on my PC on XE3 to fill screen with cells. By disabling these lines: //ProgressBar.Value:= ProgressBar.Value + 1; //Caption:= ‘Elapsed time: ‘ + FormatDateTime(‘nn:ss:zzz’, Time – T) + // ‘ (min:sec:msec) Cells: ‘ + IntToStr(Trunc(ProgressBar.Value)); … //Application.ProcessMessages; This goes down to 00:00:106 (!). Updating visual controls (such as … Read more
TOpenDialog executes TFileOpenDialog when the following conditions are met: the program is running under Vista (and up) UseLatestCommonDialogs is true (which is the default) no OnIncludeItem, OnClose or OnShow events are set So while still using TOpenDialog on your system you may likely end up automagically executing TFileOpenDialog in most cases, which explains why they … Read more
The Sort overload you should be using is this one: procedure Sort(const AComparer: IComparer<TMyRecord>); Now, you can create an IComparer<TMyRecord> by calling TComparer<TMyRecord>.Construct. Like this: var Comparison: TComparison<TMyRecord>; …. Comparison := function(const Left, Right: TMyRecord): Integer begin Result := Left.intVal-Right.intVal; end; List.Sort(TComparer<TMyRecord>.Construct(Comparison)); I’ve written the Comparison function as an anonymous method, but you could also … Read more
Is it possible to resolve the problem by tuning compiler options? No, you cannot fix the error by tuning, it’s a (very specific) bug in the compiler. [Can someone tell me] Whether this problem repeats at someone else? I can reproduce the code, but only in XE2 update 4. I was not able to check … Read more
To add a single quote to a string, you include two ‘ marks e.g. str := ”’test string”’; Writeln(str) In the string above, you have the normal single quotation to start a string and then two for the single quote. Same goes for the end of the string. You can also use # followed by … Read more
TStrings is an abstract type that doesn’t have all methods implemented. TStringList is a descendant of TStrings and implements all functions. In your code, you could declare your variable also as TStringList. However e.g. on function definitions it makes sense to accept a TStrings parameter instead of a TStringList: procedure doSomething(lst: TStrings); This enables the … Read more