[英]How to avoid this deadlock between a critical section and SendMessage?
[英]How to avoid repeated SendMessage
我有一個問題:我通過DLL中的過程使用SendMessage與主窗口進行通信; procedure是一個掛鈎過程,它使主窗口知道何時在編輯框中單擊鼠標右鍵; 它也發送編輯框的句柄。 除此錯誤外,它運行良好:當程序運行時沒有斷點時,主窗口會收到兩次相同的消息(在本例中為WM_APP),而如果我在掛鈎過程或處理WM_APP消息的塊中放入斷點,則消息為考慮一次。 有關更多說明,請問我。 遵循掛鈎過程和處理WM_APP消息的塊的代碼。 謝謝
掛鈎程序
MYDLL_API LRESULT CALLBACK mouseProc(int nCode, WPARAM wParam, LPARAM lParam)
{
// processes the message
if(nCode >= 0)
{
// if user clicked with mouse right button
if(wParam != NULL && (wParam == WM_RBUTTONDOWN || wParam == WM_RBUTTONUP))
{
wchar_t *s = (wchar_t*) malloc(CLASSNAMELEN*sizeof(wchar_t));
//MessageBox(mainHwnd, (LPCWSTR)L"Captured mouse right button", (LPCWSTR)L"Test", MB_OK);
MOUSEHOOKSTRUCT *m = (MOUSEHOOKSTRUCT*) lParam;
GetClassName(m->hwnd, (LPWSTR) s, CLASSNAMELEN);
//MessageBox(mainHwnd, (LPCWSTR) s, (LPCWSTR)L"Test", MB_OK);
// only if user clicked on a edit box
if(wcsncmp(s, L"Edit", 4) == 0)
SendMessage(mainHwnd, WM_APP, 0, (LPARAM) lParam);
free(s);
s = NULL;
}
}
// calls next hook in chain
return CallNextHookEx(NULL, nCode, wParam, lParam);
}
處理WM_APP消息的主程序中的塊
case WM_APP:
{
//MessageBox(hWnd, (LPCWSTR)L"Received WM_APP", (LPCWSTR)L"Test", MB_OK);
// copies text from the edit box
MOUSEHOOKSTRUCT *m = (MOUSEHOOKSTRUCT*) lParam;
int n = GetWindowTextLength(m->hwnd);
// if text has been inserted
if(n > 0 && n < 1024)
{
wchar_t *s = (wchar_t*) malloc((n+1)*sizeof(wchar_t));
// gets text
GetWindowText(m->hwnd, (LPWSTR) s, n+1);
s[n] = (wchar_t) 0;
//MessageBox(hWnd, (LPCWSTR)s, (LPCWSTR)L"Test", MB_OK);
// saves text in database
stateClassPointer->insertInList(s);
}
}
break;
可能是因為您要發送有關WM_RBUTTONDOWN和WM_RBUTTONUP的消息,即當按下右按鈕並釋放它時。
調試時,調試器會吃掉WM_RBUTTONUP,所以您不會得到它。
PS:為了安全起見,您不應該使用PostMessage()而不是SendMessage()嗎?
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.