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Problem with child window in C ++

I have a problem in my program whenever I close the child window, the main window also exits.

I am new to this programming.

The correct code is:

/** @file MainWindow.cpp @author Andro Bondoc @date 2011-02-11 */ /** @file MainWindow.cpp @author Andro Bondoc @date 2011-02-11 */ #include "tray.h" #define WM_USER_SHELLICON WM_USER + 1 HWND hWnd, Button, LoadNew, TextBox; HINSTANCE hInst; HICON hMainIcon; HMENU hPopMenu; NOTIFYICONDATA structNID; long PASCAL WndProcParent(HWND,UINT,UINT,LONG); long PASCAL WndProcChild(HWND,UINT,UINT,LONG); int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { MSG msg; WNDCLASS wc, ws; hInst = hInstance; if(!hPrevInstance) { wc.style = CS_HREDRAW | CS_VREDRAW; wc.lpfnWndProc = WndProcParent; wc.cbClsExtra = 0; wc.cbWndExtra = 0; wc.hInstance = hInstance; wc.hIcon = LoadIcon(hInstance,(LPCTSTR)MAKEINTRESOURCE(IDI_TRAYICON));//LoadIcon(NULL,IDI_APPLICATION); wc.hCursor = LoadCursor(NULL,IDC_ARROW); wc.hbrBackground = (HBRUSH)COLOR_BACKGROUND; wc.lpszMenuName = NULL; wc.lpszClassName = "Data Retriever Parent"; RegisterClass(&wc); ws.style = CS_HREDRAW | CS_VREDRAW; ws.lpfnWndProc = WndProcChild; ws.cbClsExtra = 0; ws.cbWndExtra = 0; ws.hInstance = hInstance; ws.hIcon = LoadIcon(hInstance,(LPCTSTR)MAKEINTRESOURCE(IDI_TRAYICON));//LoadIcon(NULL,IDI_APPLICATION); ws.hCursor = LoadCursor(NULL,IDC_ARROW); ws.hbrBackground = (HBRUSH)COLOR_BACKGROUND; ws.lpszMenuName = NULL; ws.lpszClassName = "Data Retriever Child"; RegisterClass(&ws); } hWnd = CreateWindowEx(0, wc.lpszClassName, "Data Retriever", WS_BORDER | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL); LoadNew = CreateWindowEx(0, ws.lpszClassName, "Help Program", WS_BORDER | WS_CAPTION | WS_CHILD, 120, 80, 500, 300, hWnd, NULL, hInstance, NULL); hMainIcon = LoadIcon(hInstance,(LPCTSTR)MAKEINTRESOURCE(IDI_TRAYICON)); structNID.cbSize = sizeof(NOTIFYICONDATA); structNID.hWnd = (HWND) hWnd; structNID.uID = IDI_TRAYICON; structNID.uFlags = NIF_ICON | NIF_MESSAGE; structNID.hIcon = hMainIcon; structNID.uCallbackMessage = WM_USER_SHELLICON; Shell_NotifyIcon(NIM_ADD, &structNID); while(GetMessage(&msg,NULL,0,0)) { TranslateMessage(&msg); DispatchMessage(&msg); } return msg.wParam; } long FAR PASCAL WndProcParent(HWND hwnd,UINT message,UINT wParam,long lParam) { HDC hdc = NULL; POINT lpClickPoint; char buff[100] = ""; switch(message){ case WM_CREATE: Button = CreateWindowEx(WS_EX_WINDOWEDGE, "BUTTON", "Close", WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON, 680,480, 80, 30, hwnd, (HMENU)ID_CLOSE, GetModuleHandle(NULL), NULL); Button = CreateWindowEx(WS_EX_WINDOWEDGE, "BUTTON", "Help", WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON, 680,450, 80, 30, hwnd, (HMENU)ID_HELPDAW, GetModuleHandle(NULL), NULL); break; /*case WM_DESTROY: PostQuitMessage(0); return 0;*/ case WM_USER_SHELLICON: switch(LOWORD(lParam)) { case WM_LBUTTONDBLCLK: ShowWindow(hwnd, SW_RESTORE); break; case WM_RBUTTONDOWN: //get mouse cursor position x and y as lParam has the message itself GetCursorPos(&lpClickPoint); //place the window/menu there if needed hPopMenu = CreatePopupMenu(); InsertMenu(hPopMenu,0xFFFFFFFF,MF_BYPOSITION|MF_STRING,ID_OPEN,"&Open"); InsertMenu(hPopMenu,0xFFFFFFFF,MF_BYPOSITION|MF_STRING,ID_HELPDAW,"&Help"); InsertMenu(hPopMenu,0xFFFFFFFF,MF_BYPOSITION|MF_STRING,ID_CLOSE,"&Exit"); //workaround for microsoft bug, to hide menu w/o selecting SetForegroundWindow(hWnd); TrackPopupMenu(hPopMenu,TPM_LEFTALIGN|TPM_LEFTBUTTON|TPM_BOTTOMALIGN,lpClickPoint.x, lpClickPoint.y,0,hWnd,NULL); SendMessage(hWnd,WM_NULL,0,0); //MessageBox(NULL,"TEST rightclick","Testing ...",MB_OK); return TRUE; } break; case WM_COMMAND: if(ID_CLOSE == LOWORD(wParam)) { int iRes = MessageBox(NULL,"Do you want to Exit","Data Retriever",MB_YESNO|MB_ICONQUESTION); if(IDYES == iRes) { Shell_NotifyIcon(NIM_DELETE,&structNID); DestroyWindow(hWnd); PostQuitMessage(0); } } else if(ID_HELPDAW == LOWORD(wParam)) { ShowWindow(LoadNew, SW_SHOW); //MessageBox(NULL, "Help","Data Retriever",MB_OK|MB_ICONQUESTION); } else if(ID_OPEN == LOWORD(wParam)) { ShowWindow(hWnd, SW_NORMAL); } break; case WM_CLOSE: Shell_NotifyIcon(NIM_DELETE,&structNID); DestroyWindow(hWnd); PostQuitMessage(0); break; case WM_SYSCOMMAND: if(SC_MINIMIZE == wParam) { ShowWindow(hWnd,SW_HIDE); return TRUE; } break; } return DefWindowProc(hwnd,message,wParam,lParam); } long FAR PASCAL WndProcChild(HWND hwnd,UINT message,UINT wParam,long lParam){ HDC hdc = NULL; PAINTSTRUCT ps; char buff[100] = ""; switch(message){ case WM_CREATE: Button = CreateWindowEx(WS_EX_WINDOWEDGE, "BUTTON", "Unload", WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON, 20,20, 80, 30, hwnd, (HMENU)ID_MESSAGE, GetModuleHandle(NULL), NULL); break; case WM_COMMAND: if(ID_RETURN == LOWORD(wParam)) { ShowWindow(hWnd, SW_SHOW); ShowWindow(LoadNew,SW_HIDE); //MessageBox(NULL, "Help","Data Retriever",MB_OK|MB_ICONQUESTION); } case WM_CLOSE: ShowWindow(hWnd, SW_SHOW); ShowWindow(LoadNew,SW_HIDE); break; case WM_PAINT: RECT rect; GetClientRect(LoadNew,&rect); hdc = BeginPaint(LoadNew,&ps); strcpy_s(buff,"TOP"); DrawText(hdc,buff,strlen(buff), &rect,DT_SINGLELINE|DT_CENTER|DT_TOP); strcpy_s(buff,"RIGHT"); DrawText(hdc,buff,strlen(buff), &rect,DT_SINGLELINE|DT_VCENTER|DT_RIGHT); strcpy_s(buff,"BOTTOM"); DrawText(hdc,buff,strlen(buff), &rect,DT_SINGLELINE|DT_CENTER|DT_BOTTOM); strcpy_s(buff,"LEFT"); DrawText(hdc,buff,strlen(buff), &rect,DT_SINGLELINE|DT_VCENTER|DT_LEFT); strcpy_s(buff,"CENTER"); DrawText(hdc,buff,strlen(buff), &rect,DT_SINGLELINE|DT_CENTER|DT_VCENTER); strcpy_s(buff,"BOTTOM-LEFT"); DrawText(hdc,buff,strlen(buff), &rect,DT_SINGLELINE|DT_BOTTOM|DT_LEFT); strcpy_s(buff,"BOTTOM-RIGHT"); DrawText(hdc,buff,strlen(buff), &rect,DT_SINGLELINE|DT_BOTTOM|DT_RIGHT); strcpy_s(buff,"TOP-LEFT"); DrawText(hdc,buff,strlen(buff), &rect,DT_SINGLELINE|DT_TOP|DT_LEFT); strcpy_s(buff,"TOP-RIGHT"); DrawText(hdc,buff,strlen(buff), &rect,DT_SINGLELINE|DT_TOP|DT_RIGHT); EndPaint(LoadNew,&ps); break; } return DefWindowProc(hwnd,message,wParam,lParam); }
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2 answers

Your modified code still uses the same WndProc for both windows. You tried twice to call RegisterClass with the same class name. WndProcs will not be split until you change the name.

 ws.lpszClassName = "Data Retriever CHILD";

This problem would be more obvious if you checked the return value from RegisterClass - currently the second call fails. Other problems with this code (for example, calling MessageBox on a child of WndProc is really unpleasant), but this change should be enough for you to go in the right direction.

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You have the same wndproc code for each window. For WM_CLOSE you are DestroyWindow (hWnd), where hWnd is the global one in which your main window is stored.

So, closing your child window closes the main window because you told him.

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Source: https://habr.com/ru/post/1339777/

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