setTimeout是有用的JavaScript语言.你将如何在delphi中创建这个函数？
SetTimeOut(procedure (Sender: TObject); begin Self.Counter := Self.Counter + 1; end,200);
解决方法
我想你可能会原谅
TTimer,并尝试使用
SetTimer功能并使用其回调功能.您需要将定时器ID及其(匿名)方法存储在某些集合中.既然你没有提到你的Delphi版本,我使用了一个简单的类和
TObjectList作为一个集合.
原理很简单,您只需使用指定的回调函数调用SetTimer函数,并将具有匿名方法的新实例化系统定时器ID存储到集合中.当执行该回调函数时,找到定时器,它通过其ID来导致集合中的回调,将其删除,执行匿名方法并将其从集合中删除.以下是示例代码：
unit Unit1;
interface
uses
Windows,Messages,SysUtils,Variants,Classes,Graphics,Controls,Forms,Dialogs,ExtCtrls,StdCtrls,Contnrs;
type
TOnTimerProc = reference to procedure;
TOneShotTimer = class
ID: UINT_PTR;
Proc: TOnTimerProc;
end;
procedure SetTimeout(AProc: TOnTimerProc; ATimeout: Cardinal);
type
TForm1 = class(TForm)
Timer1: TTimer;
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
TimerList: TObjectList;
implementation
{$R *.dfm}
procedure TimerProc(hwnd: HWND; uMsg: UINT; idEvent: UINT_PTR;
dwTime: DWORD); stdcall;
var
I: Integer;
Timer: TOneShotTimer;
begin
for I := 0 to TimerList.Count - 1 do
begin
Timer := TOneShotTimer(TimerList[I]);
if Timer.ID = idEvent then
begin
KillTimer(0,idEvent);
Timer.Proc();
TimerList.Delete(I);
Break;
end;
end;
end;
procedure SetTimeout(AProc: TOnTimerProc; ATimeout: Cardinal);
var
Timer: TOneShotTimer;
begin
Timer := TOneShotTimer.Create;
Timer.ID := SetTimer(0,ATimeout,@TimerProc);
Timer.Proc := AProc;
TimerList.Add(Timer);
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
SetTimeout(procedure
begin
ShowMessage('OnTimer');
end,1000
);
end;
initialization
TimerList := TObjectList.Create;
TimerList.OwnsObjects := True;
finalization
TimerList.Free;
end.
简化版(Delphi2009)：
像@ David的评论一样,这里是与上述相同的代码,只是在使用泛型字典的单独的单元中.来自本机的SetTimeout的使用与上述代码相同：
unit OneShotTimer;
interface
uses
Windows,Generics.Collections;
type
TOnTimerProc = reference to procedure;
procedure SetTimeout(AProc: TOnTimerProc; ATimeout: Cardinal);
var
TimerList: TDictionary<UINT_PTR,TOnTimerProc>;
implementation
procedure TimerProc(hwnd: HWND; uMsg: UINT; idEvent: UINT_PTR;
dwTime: DWORD); stdcall;
var
Proc: TOnTimerProc;
begin
if TimerList.TryGetValue(idEvent,Proc) then
try
KillTimer(0,idEvent);
Proc();
finally
TimerList.Remove(idEvent);
end;
end;
procedure SetTimeout(AProc: TOnTimerProc; ATimeout: Cardinal);
begin
TimerList.Add(SetTimer(0,@TimerProc),AProc);
end;
initialization
TimerList := TDictionary<UINT_PTR,TOnTimerProc>.Create;
finalization
TimerList.Free;
end.