我在另一個類中創建了一個子窗口,所以我將父窗口的hWnd和hInstance傳遞給了我創建子窗口的函數。Win32 CreateWindow()error,this is nullptr
我現在的問題是,子窗口的createWindow()函數掛起,我收到一條錯誤消息,它說:「異常已遇到,可能是由擴展造成的。
有人知道這個信息是什麼意思,或者我做錯了什麼?
在這裏,我在父窗口的消息處理程序中調用子窗口,因爲我使用的是具有ID的子菜單。
LRESULT CALLBACK System::MessageHandler(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam)
{
MainMenu mMainMenu;
switch (message)
{
case WM_COMMAND:
{
switch (LOWORD(wparam))
{
//If user presses on the exit button
case IDM_FILE_EXIT:
{
PostQuitMessage(0);
} break;
case IDM_NEW_NEWPROJECT:
{
//////////////////////////////////////////////
// Here is the error showing up
//////////////////////////////////////////////
m_CreateProjectMenu->Initialize(m_hWnd, m_hinstance);
}break;
default:
break;
}
}
// Any other messages send to the default message handler as our application won't make use of them.
default:
{
return DefWindowProc(hwnd, message, wparam, lparam);
}
}
}
初始化:
bool CreateProjectMenu::Initialize(HWND m_ParentWindow, HINSTANCE m_hParentInstance)
{
//Initialize the window
InitializeWindow(m_ParentWindow, m_hParentInstance);
return true;
}
InitializeWindow:
void CreateProjectMenu::InitializeWindow(HWND m_ParentWindow, HINSTANCE m_hParentInstance)
{
wc.style = CS_HREDRAW | CS_VREDRAW; // Defines additional elements of the window class.
wc.lpfnWndProc = ChildProc; // A pointer to the window procedure.
wc.cbClsExtra = 0; // The number of extra bytes to allocate following the window-class structure.
wc.cbWndExtra = 0; // The number of extra bytes to allocate following the window instance.
wc.hInstance = m_hParentInstance; // A handle to the instance that contains the window procedure.
wc.hIcon = LoadIcon(wc.hInstance, IDI_APPLICATION); // Load the icon for the application.
wc.hCursor = LoadCursor(NULL, IDC_ARROW); // Load the cursor for the application.
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1); // Load the background for the application.
wc.lpszMenuName = NULL; // Pointer to a character string that specifies the name of the resource class menu.
wc.lpszClassName = m_ProjectMenuWindowName; // Set the name for the window.
wc.hInstance = m_hParentInstance;
if (!RegisterClass(&wc))
{
MessageBox(NULL, L"Failed to register the menuprojectwindow", L"Error", MB_OK);
}
m_NewProjectHwnd = CreateWindow(NULL,
m_ProjectMenuWindowName,
WS_CHILD | WS_VISIBLE | WS_CAPTION
| WS_SYSMENU | WS_THICKFRAME
| WS_MINIMIZEBOX | WS_MAXIMIZEBOX,
CW_USEDEFAULT,
CW_USEDEFAULT,
screenWidth, screenHeight,
m_ParentWindow,
NULL,
m_hParentInstance,
NULL);
// Check if the hwnd is zero(error)
// Display a messagebox with a error
if (m_NewProjectHwnd == 0)
MessageBox(NULL, L"Could not create the create project hwnd.", L"Error", MB_OK);
else
{
ShowWindow(m_NewProjectHwnd, SW_SHOW); // Bring the window up on the screen
SetFocus(m_NewProjectHwnd);
}
return;
}
這裏是重現該錯誤的代碼: https://ufile.io/ddmj4
您發佈的錯誤消息是由Visual Studio錯誤引起的。代碼似乎沒問題。目前還不清楚「這是nullptr」與問題內容有關。在哪裏'this'是'nullptr'? – VTT
當我在parentmessagehandler中調用initializeWindow函數時,visual studio錯誤顯示出來,我真的不知道爲什麼,因爲這從來沒有發生過,所以我不知道是什麼導致了問題。我還搜索了對於這樣的錯誤網絡,但似乎沒有人有這個呢。 – MystikReasons