如何实现同一个应用程序只能打开一次

Delphi(Pascal) code

var  aHandle: THandle;begin  aHandle := CreateMutex(nil, TRUE, ' ');  if (aHandle <> 0) and (GetLastError = ERROR_ALREADY_EXISTS) then  begin    Application.MessageBox('程序已经运行!', '提示!', MB_OK);    CloseHandle(aHandle);  end  else  begin    Application.Initialize;    Application.MainFormOnTaskbar := True;    Application.CreateForm(TfrmSearchFormPath, frmSearchFormPath);  end;  Application.Run;end.

这样虽然能找到该应用程序是否打开
但不能定位到该程序窗体
请各位帮忙修改实现（单窗体的）

[解决办法]
决定拿你的分，你的问题由我来解决

Delphi(Pascal) code

program cpglt;uses  windows,  Forms;{$R *.res}varhAppMutex: THandle;begin  Application.Initialize;  hAppMutex := CreateMutex(nil, false, PChar(‘文件唯一的名称，可以随便你用’));  if (hAppMutex = 0) then  begin    exit;  end;  if ((hAppMutex <> 0) and (GetLastError() = ERROR_ALREADY_EXISTS)) then  begin    //MessageBox(0,PChar('不是第一次运行这个程序!'),PChar('OK'),MB_OK + MB_ICONINFORMATION);    CloseHandle(hAppMutex);    exit;  end;  Application.Title := '彩票电脑规律';  Application.CreateForm(TForm1, Form1);  Application.Run;  //关闭互斥对象  CloseHandle(hAppMutex);end.
[解决办法]
我来接分，给你个单元
Delphi(Pascal) code
unit UnicoughOneInst;interfaceuses SysUtils;type  EUnicough_MultInstError = class(Exception);procedure SetMultInstState(const AllowMultInst: Boolean);function IsMultInstAllowed: Boolean;implementationuses Windows, Forms;const  MI_GETMULTINSTSTATE = 0;  MI_RESPONDMULTINSTSTATE = 1;var  MultInstAllowed: Boolean = false;  MutHandle: Integer;  OldWProc: TFNWndProc;  MI_ACTIVATE: Integer;procedure SetMultInstState(const AllowMultInst: Boolean);begin  MultInstAllowed := AllowMultInst;end;function IsMultInstAllowed: Boolean;begin  Result := MultInstAllowed;end;function NewWndProc(Handle: HWND; Msg: Integer; wParam, lParam: Longint):  Longint; stdcall;begin  Result := 0;  if Msg = MI_ACTIVATE then    case wParam of      MI_GETMULTINSTSTATE:      begin        if not MultInstAllowed then        begin          Application.MainForm.WindowState := wsNormal;          Application.Restore;          PostMessage(HWND(lParam), MI_ACTIVATE, MI_RESPONDMULTINSTSTATE, Application.MainForm.Handle);        end else          PostMessage(HWND(lParam), MI_ACTIVATE, MI_RESPONDMULTINSTSTATE, 0);              end;      MI_RESPONDMULTINSTSTATE:        if lParam <> 0 then        begin          SetForegroundWindow(HWND(lParam));          Application.Terminate;        end else          Application.MainForm.Visible := true;    end  else    Result := CallWindowProc(OldWProc, Handle, Msg, wParam, lParam);end;procedure DoFirstInstance;begin  MutHandle := CreateMutex(nil, False, PChar(Application.Title));  if MutHandle = 0 then    raise EUnicough_MultInstError.Create('无法创建互斥!');end;procedure BroadcastFocusMessage;var  BSMRecipients: DWORD;begin  Application.ShowMainForm := False;  BSMRecipients := BSM_APPLICATIONS;  BroadCastSystemMessage(BSF_IGNORECURRENTTASK or BSF_POSTMESSAGE, @BSMRecipients, MI_ACTIVATE, MI_GETMULTINSTSTATE, Application.Handle);end;procedure InitInstance;begin  OldWProc := TFNWndProc(SetWindowLong(Application.Handle, GWL_WNDPROC, Longint(@NewWndProc)));  if OldWProc = nil then    raise EUnicough_MultInstError.Create('无法获取消息循环!');  MutHandle := OpenMutex(MUTEX_ALL_ACCESS, False, PChar(Application.Title));  if MutHandle = 0 then    DoFirstInstance  else    BroadcastFocusMessage;end;initialization  MI_ACTIVATE := RegisterWindowMessage(PChar(Application.Title));  InitInstance;finalization  if OldWProc <> nil then    SetWindowLong(Application.Handle, GWL_WNDPROC, Longint(OldWProc));  if MutHandle <> 0 then CloseHandle(MutHandle);end.