WIN32,两个窗口使用相同的 wndproc.为什么
WIN32, Two windows using the same wndproc...why?
我正在尝试制作两个使用两个不同 wndproc 的窗口。我创建了两个单独的 wndproc 和两个单独的窗口类,它们指向它们自己的 wndproc 回调。
但是由于某种原因,两个窗口都使用相同的wndproc。从技术上讲,我的第二个窗口应该使用 WndProcControl,但是它使用 WndProc,就像我的第一个窗口一样......
为什么要这样做? 这是我的代码:
// Edit.cpp : Defines the entry point for the application.
//
#include "stdafx.h"
#include "TaylorSoundEditor.h"
#define MAX_LOADSTRING 100
// Global Variables:
HINSTANCE hInst; // current instance
TCHAR szTitle[MAX_LOADSTRING]; // The title bar text
TCHAR szControl[MAX_LOADSTRING]; //The title bar for the Control window
TCHAR szWindowClass[MAX_LOADSTRING]; // the main window class name
TCHAR szControlClass[MAX_LOADSTRING]; //the control window class name
// Forward declarations of functions included in this code module:
ATOM MyRegisterClass(HINSTANCE hInstance);
ATOM MyRegisterControlClass(HINSTANCE hInstance);
BOOL InitInstance(HINSTANCE, int);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK WndProcControl(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK About(HWND, UINT, WPARAM, LPARAM);
int APIENTRY _tWinMain(_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPTSTR lpCmdLine,
_In_ int nCmdShow)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
// TODO: Place code here.
MSG msg;
HACCEL hAccelTable;
// Initialize global strings
LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
LoadString(hInstance, IDS_CONTROL_TITLE, szControl, MAX_LOADSTRING);
LoadString(hInstance, IDC_TAYLORSOUNDEDITOR, szWindowClass, MAX_LOADSTRING);
LoadString(hInstance, IDC_TAYLORSOUNDEDITOR, szControlClass, MAX_LOADSTRING);
MyRegisterClass(hInstance);
MyRegisterControlClass(hInstance);
// Perform application initialization:
if (!InitInstance (hInstance, nCmdShow))
{
return FALSE;
}
hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_TAYLORSOUNDEDITOR));
// Main message loop:
while (GetMessage(&msg, NULL, 0, 0))
{
if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
return (int) msg.wParam;
}
//
// FUNCTION: MyRegisterClass()
//
// PURPOSE: Registers the window class.
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
WNDCLASSEX wcex;
wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_TAYLORSOUNDEDITOR));
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName = MAKEINTRESOURCE(IDC_TAYLORSOUNDEDITOR);
wcex.lpszClassName = szWindowClass;
wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));
return RegisterClassEx(&wcex);
}
ATOM MyRegisterControlClass(HINSTANCE hInstance)
{
WNDCLASSEX controlex;
controlex.cbSize = sizeof(WNDCLASSEX);
controlex.style = CS_HREDRAW | CS_VREDRAW;
controlex.lpfnWndProc = WndProcControl;
controlex.cbClsExtra = 0;
controlex.cbWndExtra = 0;
controlex.hInstance = hInstance;
controlex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_TAYLORSOUNDEDITOR));
controlex.hCursor = LoadCursor(NULL, IDC_ARROW);
controlex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
controlex.lpszMenuName = MAKEINTRESOURCE(IDC_TAYLORSOUNDEDITOR);
controlex.lpszClassName = szControlClass;
controlex.hIconSm = LoadIcon(controlex.hInstance, MAKEINTRESOURCE(IDI_SMALL));
return RegisterClassEx(&controlex);
}
//
// FUNCTION: InitInstance(HINSTANCE, int)
//
// PURPOSE: Saves instance handle and creates main window
//
// COMMENTS:
//
// In this function, we save the instance handle in a global variable and
// create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
HWND hWnd, controlWnd;
hInst = hInstance; // Store instance handle in our global variable
hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);
controlWnd = CreateWindow(szControlClass, szControl, WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);
if (!hWnd)
{
return FALSE;
}
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
ShowWindow(controlWnd, nCmdShow);
UpdateWindow(controlWnd);
return TRUE;
}
//
// FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
// PURPOSE: Processes messages for the main window.
//
// WM_COMMAND - process the application menu
// WM_PAINT - Paint the main window
// WM_DESTROY - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int wmId, wmEvent;
PAINTSTRUCT ps;
HDC hdc;
switch (message)
{
case WM_CREATE:
MessageBox(hWnd, L"TEXT", L"TESTTT", 0);
break;
case WM_COMMAND:
wmId = LOWORD(wParam);
wmEvent = HIWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_ABOUT:
DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
break;
case WM_PAINT:
hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code here...
EndPaint(hWnd, &ps);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
LRESULT CALLBACK WndProcControl(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int wmId, wmEvent;
PAINTSTRUCT ps;
HDC hdc;
switch (message)
{
case WM_CREATE:
MessageBox(hWnd, L"TEXT2", L"TESTTT2", 0);
CreateWindow(TEXT("button"), TEXT("hello"), WS_VISIBLE | WS_CHILD, 0, 0, 200, 85, hWnd, (HMENU) 1, NULL, NULL);
break;
case WM_COMMAND:
wmId = LOWORD(wParam);
wmEvent = HIWORD(wParam);
case WM_PAINT:
hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code here...
EndPaint(hWnd, &ps);
break;
case WM_DESTROY:
//PostQuitMessage(0);
break;
}
return DefWindowProc(hWnd, message, wParam, lParam);
}
// Message handler for about box.
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
UNREFERENCED_PARAMETER(lParam);
switch (message)
{
case WM_INITDIALOG:
return (INT_PTR)TRUE;
case WM_COMMAND:
if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
{
EndDialog(hDlg, LOWORD(wParam));
return (INT_PTR)TRUE;
}
break;
}
return (INT_PTR)FALSE;
}
您尝试注册两个窗口类。但是你给它们都指定了相同的类名。所以第二次尝试失败了。然后创建两个窗口,将相同的窗口类名传递给对 CreateWindow
的两个调用。
看看你给LoadString
打的电话。
LoadString(hInstance, IDC_TAYLORSOUNDEDITOR, szWindowClass, MAX_LOADSTRING);
LoadString(hInstance, IDC_TAYLORSOUNDEDITOR, szControlClass, MAX_LOADSTRING);
显然,这样做的结果是szWindowClass
和szControlClass
具有相同的价值。
如果您没有忽略对 RegisterClassEx
的调用的返回值,您自己就会发现这一点。由于显而易见的原因,第二次调用失败。不要忽略返回值!
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