library Project2;
uses
  SysUtils,
  Classes,
  Unit1 in 'Unit1.pas';
{$R *.res}
begin
xzcx;
end.

unit Unit1;
interface
uses Windows,SysUtils;
var
  t1: LongWord=0; // 定时器句柄
procedure xzcx();
procedure TimerOn;  // 安装定时器
procedure TimerOff; // 删除定时器
implementation
Procedure WriteTxt(sFileName,sText:String); //写txt文件
Var
F:TextFile;
Begin
AssignFile(F,sFileName);
IF FileExists(sFileName) Then
Append(F)
Else
ReWrite(F);
WriteLn(F,sText);
CloseFile(F);
End;
procedure TimerProc(hWnd: HWND; uMsg: UINT; idEvent: UINT; dwTime: DWORD); stdcall;
begin
WriteTxt('0.txt','正在执行定时器'+ inttostr(t1));
end;
procedure xzcx();
begin
TimerOn;
WriteTxt('0.txt','启动定时器'+ inttostr(t1));
end;
procedure TimerOn;
begin
  if (t1 <> 0) then TimerOff;
  t1:= SetTimer(0, 0, 100, @TimerProc);
end;
procedure TimerOff;
begin
  if (t1 <> 0) then
  begin
    KillTimer(0, t1);
    t1 := 0;
  end;
end;
end.

结果
启动定时器28535
启动定时器32759
没有执行,为什么会这样呢?

[招生]科锐逆向工程师培训(2024年11月15日实地，远程教学同时开班, 第51期)