Delphi

问题 What's the best algorithm to find the smallest non zero positive value from a fixed number (in this case 3) of values or return 0 if there are no positive questions? My naive approach is below (in Delphi, but feel free to use whatever you like), but I think there's a more elegant way. value1Temp := MaxInt; value2Temp := MaxInt; value3Temp := MaxInt; if ( value1T > 0) then value1Temp := value1; if ( value2 > 0) then value2Temp := value2; if ( value3 > 0) then value3Temp := value3; Result :=

问题 How to add TMenuItem under Project1 and above Quit on the screenshot below? I have created a TMenuBar with property UseOSMenu checked. The first TMenuItem I added is the second one in the main bar... 回答1: You can do this by assigning a TMenuBar of IItemsContainer implementing class to the Application.ApplicationMenuItems property. Example: If there was a menu bar component on the form called MenuBar1, then you would just call the following in your forms constructor (or OnCreate). Application

问题 I have a class inside my DLL. And this DLL provides an "interface" to create objects of this class and call their methods. Class code (simplified): TLogger = class private // public function AddToLog(sBuf: PWideChar): Word; constructor Create(Name: PWideChar); destructor Destroy; override; end; constructor Create(Name: PWideChar); begin // end; destructor TLogger.Destroy; begin // end; function TLogger.AddToLog(sBuf: PWideChar): Word; var Temp1 : WideString; Temp2 : AnsiString; begin Result :

问题 I have a class inside my DLL. And this DLL provides an "interface" to create objects of this class and call their methods. Class code (simplified): TLogger = class private // public function AddToLog(sBuf: PWideChar): Word; constructor Create(Name: PWideChar); destructor Destroy; override; end; constructor Create(Name: PWideChar); begin // end; destructor TLogger.Destroy; begin // end; function TLogger.AddToLog(sBuf: PWideChar): Word; var Temp1 : WideString; Temp2 : AnsiString; begin Result :

问题 i have an old application (started in delphi 7 in Win XP), now i'm using delphi 2009 (win Vista). If i start a new project all buttons have a rouded edge, but in my old app all buttons have a "square"-shape look. is there any setting that i've missed? thanks 回答1: Under the Project Options in D2009, there is an "Enable runtime themes" option which is ticked by default for new projects but unticked for pre-existing projects. Ticking this adds the manifest file to the EXE's resource, which is

问题 I expect the following code to work: program Project3; {$APPTYPE CONSOLE} {$R *.res} uses System.SysUtils; var FS: TFormatSettings; const DF = 'yyyymmdd'; begin try WriteLn(FormatDateTime(DF, Now)); FS := TFormatSettings.Create; FS.ShortDateFormat := DF; WriteLn(StrToDate('20121219', FS)); ReadLn; except on E: Exception do Writeln(E.ClassName, ': ', E.Message); end; end. Why is it throwing an exception, saying that '20121219' is not a valid date? Isn't that exactly what passing the

问题 In a single-threaded application I use code like this: Interface function GetNextUID : integer; Implementation function GetNextUID : integer; const cUID : integer = 0; begin inc( cUID ); result := cUID; end; This could of course be implemented as a singleton object, etc. - I'm just giving the simplest possible example. Q: How can I modify this function (or design a class) to achieve the same result safely from concurrent threads? 回答1: You can use the Interlocked* functions: function

问题 Please help with the following: ERROR : too many actual parameters on calling class procedure line. Main UNIT: procedure TForm1.btnbtbtn1Click(Sender: TObject); var bwagwoord,bemail :boolean ; epos,wagwoord,safvoer :String ; begin Form2.qryreg.Close; form2.qryreg.SQL.Text := 'select * from registertb '; form2.qryreg.open ; epos := edt1.text ; wagwoord := edt2.text ; safvoer := ' '; bemail :=form2.qryreg.locate ('Email',epos,[]); bwagwoord := form2.qryreg.Locate('Wagwoord',wagwoord,[]); Login

问题 I have a big Delphi 2007 project, and I use AsyncCall I have extracted and tested the multithreading code in a single console application and everything works fine. My Delphi 2007 project produces a COM DLL and I have some unit tests that are written in C# - mstest that calls the DLL. The unit tests hang quite often randomly (tests passed) and i found out it happens at the AsyncCall unit - finalizatoin section that frees the ThreadPool. destructor TThreadPool.Destroy; var I: Integer; Call:

问题 I have two applications in Delphi for which I don't have any code source: I use an interface from application A to call an DLL file from application B. Example, I usually pass a service number, 200011, from interface A to call DLL file B for a value return. But, recently the application A have changed the variable. I have to add P00200011 to call DLL file B. I have tried to create an DLL C#, but the DLL in B is created with the fastcall convention and I cannot change this DLL file. What are