我使用互联网上的源代码创建了一个GLOBAL键盘钩子DLL。最好的部分是它非常出色,除了浏览器。
它接收浏览器中的每个键,除了看起来,当浏览器获得焦点时,它会丢失按下的第一个键。在IE和Firefox中对此进行了测试,两者似乎相同。
例如,如果我打开IE并开始输入www。 ,我只回来了。如果浏览器窗口保持清晰,则不会丢失其他密钥。一旦浏览器失去焦点并重新获得焦点,第一个键就会再次丢失。
可能是因为仅使用WH_KEYDOWN而不是WH_KEYPRESS / WH_KEYUP?有人可以对此有所了解吗?
谢谢
PS:钩子函数本身如下:DLL发送一个备忘录框和应用程序句柄,DLL将发送消息以及用户消息。
function KeyHookFunc(Code, VirtualKey, KeyStroke: Integer): LRESULT; stdcall;
var
KeyState1: TKeyBoardState;
AryChar: array[0..1] of Char;
Count: Integer;
begin
Result := 0;
if Code = HC_NOREMOVE then Exit;
Result := CallNextHookEx(hKeyHook, Code, VirtualKey, KeyStroke);
{I moved the CallNextHookEx up here but if you want to block
or change any keys then move it back down}
if Code < 0 then
Exit;
if Code = HC_ACTION then
begin
if ((KeyStroke and (1 shl 30)) <> 0) then
if not IsWindow(hMemo) then
begin
{I moved the OpenFileMapping up here so it would not be opened
unless the app the DLL is attatched to gets some Key messages}
hMemFile := OpenFileMapping(FILE_MAP_WRITE, False, 'NetParentMAP');//Global7v9k
PHookRec1 := MapViewOfFile(hMemFile, FILE_MAP_WRITE, 0, 0, 0);
if PHookRec1 <> nil then
begin
hMemo := PHookRec1.MemoHnd;
hApp := PHookRec1.AppHnd;
end;
end;
if ((KeyStroke AND (1 shl 31)) = 0) then //if ((KeyStroke and (1 shl 30)) <> 0) then
begin
GetKeyboardState(KeyState1);
Count := ToAscii(VirtualKey, KeyStroke, KeyState1, AryChar, 0);
if Count = 1 then
begin
SendMessage(hMemo, WM_CHAR, Ord(AryChar[0]), 0);
{I included 2 ways to get the Charaters, a Memo Hnadle and
a WM_USER+1678 message to the program}
PostMessage(hApp, WM_USER + 1678, Ord(AryChar[0]), 0);
end;
end;
end;
end;
答案 0 :(得分:8)
您没有及早分配hMemo
和hApp
值。您正在等待“先前状态”标志为1的通知,该通知表示某个键已被按下至少1次重复计数,或者正在被释放,以先发生者为准。因此,当您的挂钩检测到其第一个按键通知时,hMemo
和hApp
尚不可用。这就是你错过角色的原因。试试这个:
function KeyHookFunc(Code, VirtualKey, KeyStroke: Integer): LRESULT; stdcall;
var
KeyState1: TKeyBoardState;
AryChar: array[0..1] of Char;
Count: Integer;
begin
Result := CallNextHookEx(hKeyHook, Code, VirtualKey, KeyStroke);
if Code <> HC_ACTION then Exit;
{ a key notification had occured, prepare the HWNDs
before checking the actual key state }
if (hMemo = 0) or (hApp = 0) then
begin
if hMemFile = 0 then
begin
hMemFile := OpenFileMapping(FILE_MAP_WRITE, False, 'NetParentMAP');
if hMemFile = 0 then Exit;
end;
if PHookRec1 = nil then
begin
PHookRec1 := MapViewOfFile(hMemFile, FILE_MAP_WRITE, 0, 0, 0);
if PHookRec1 = nil then Exit;
end;
hMemo := PHookRec1.MemoHnd;
hApp := PHookRec1.AppHnd;
if (hMemo = 0) and (hApp = 0) then Exit;
end;
if ((KeyStroke and (1 shl 31)) = 0) then // a key is down
begin
GetKeyboardState(KeyState1);
Count := ToAscii(VirtualKey, KeyStroke, KeyState1, AryChar, 0);
if Count = 1 then
begin
if hMemo <> 0 then SendMessage(hMemo, WM_CHAR, Ord(AryChar[0]), 0);
if hApp <> 0 then PostMessage(hApp, WM_USER + 1678, Ord(AryChar[0]), 0);
end;
end;
end;