ActiveX控件在IE中不响应Backspace消息

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1、操作输入法需要导入：

#include <imm.h>#pragma comment(lib, "imm32")

2、定义变量：

//键盘钩子句柄HHOOK g_hKeyboardHook = NULL;//是否拦截Backspacebool g_bInterceptBackspace = true;

3、定义键盘钩子回调函数：

LRESULT CALLBACK KeyboardHookProc(int nCode, WPARAM wParam, LPARAM lParam){if (nCode > -1){BOOL bRet = FALSE;LPKBDLLHOOKSTRUCT lpKeyboard = (LPKBDLLHOOKSTRUCT)lParam;HWND hCurWnd = ::GetFocus();HIMC hImc = ImmGetContext(hCurWnd);LONG nSize = ImmGetCompositionString(hImc, GCS_COMPSTR, NULL, 0);

ImmReleaseContext(hCurWnd, hImc);if (hImc){if (nSize > 0){//如果按键组合窗口字符串长度大于0，则表明显示了按键组合窗口，交给系统默认处理g_bInterceptBackspace = false;bRet = TRUE;}else if (nSize == 0){if (!g_bInterceptBackspace){//如果按键组合框窗口字符串等于0，且上次显示了按键组合框窗口，则表明是删除最后一个字符后，交给系统默认处理g_bInterceptBackspace = true;bRet = TRUE;}}}

if (VK_BACK == wParam){if (!bRet){if (lParam & 0x80000000){::SendMessage(::GetFocus(), WM_KEYUP, VK_BACK, 0);}else{::SendMessage(hCurWnd, WM_KEYDOWN, VK_BACK, 0);::SendMessage(hCurWnd, WM_CHAR, VK_BACK, 0);}return 1;}}}return CallNextHookEx(g_hKeyboardHook, nCode, wParam, lParam);}

4、安装钩子

g_hKeyboardHook = ::SetWindowsHookEx(WH_KEYBOARD, (HOOKPROC)KeyboardHookProc, 0, GetCurrentThreadId());

5、卸载钩子

::UnhookWindowsHookEx(g_hKeyboardHook);