通过互斥对象实现 只运行一个实例

//加上 Windows单元

var
hAppMutex: THandle;

begin
  Application.Initialize;
  hAppMutex := CreateMutex(nil, false,'PaiWeiControl');
  if (hAppMutex = 0) then
  begin
    MessageBox(0,'创建互斥对象失败!','Error',MB_OK + MB_ICONINFORMATION );
    Exit;
  end;
  if ((hAppMutex <> 0) and (GetLastError() = ERROR_ALREADY_EXISTS)) then
  begin
    MessageBox(0,'只能运行一个相同程序!','Error',MB_OK + MB_ICONINFORMATION );
    CloseHandle(hAppMutex);
    Exit;
  end;
  Application.CreateForm(Tlogout, logout);
  Application.Run;
  CloseHandle(hAppMutex);
end.