我自己的C++框架(类似MFC),我可以创建子窗口,但不能在WM_create时创建编辑框
My Own C++Framework (MFC-like), i can create child window, but cant create edit box when WM_CREATE
我构建了自己的c++框架,与MFC类似,我可以在收到WM_create消息时创建子窗口,但我不能处理Edit Box,我是从Ivan Shcherbakov的帖子中得到的想法,我在调用OnCreate后发布了WM_CREATEMYWINDOW消息,并在收到消息时在OnCreateMyWindow函数中创建一些东西,当然,它是有效的。但我想知道为什么以及如何解决这个问题。
我的CWnd是CMyWindow,我创建了一个CBT钩子来保存新窗口的HWND和CMyWindow*,然后添加到HWND-window映射中作为WindowManager,消息循环回调函数MyWndProc,通过HWND参数从WindowManger中获取CMyWindow*,然后调用CMyWindow的消息函数OnCreate、OnSize、OnMove。。。,等等,就像CWnd类一样。
CMyWindow似乎工作得很好,它可以容纳所有消息并做一些响应,但当WM_create时,它不能创建编辑框,因为它是有线的,因为它在WM_create时创建了一个具有任何样式的新窗口。
我用vs2010,win7构建了它。
MyWindow.h中的WindowManager(HWND-WINDOW映射)
#define WM_CREATEMYWINDOW WM_USER + 123
//the CWindowManager is a map of HWND-CMyWindow
class CMyWindow;
//define the HWND-CMyWindow map
typedef map <HWND, CMyWindow*> CWindowMap;
typedef pair<HWND, CMyWindow*> WindowPair;
typedef map <HWND, CMyWindow*>::iterator WndIterator;
typedef pair<WndIterator, bool> IterBool;
class CWindowManager : private CWindowMap
{
private:
CWindowManager(void);
~CWindowManager(void);
public:
bool Add(CMyWindow* pwnd); //add a window to map
bool Remove(HWND hwnd); //remove a window by hwnd
void Clear(); //remove all items
CMyWindow* Find(HWND hwnd); //find the window by hwnd
public:
//get CWindowManager instance as singleton pattern
static CWindowManager * GetInstance();
};
CMyWindow类与MFC的CWnd类似
class CMyWindow
{
public:
CMyWindow(void);
~CMyWindow(void);
inline HWND GetSafeHwnd(); //get HWND
//Create a window
bool Create( HINSTANCE hInstance,
TCHAR * szWindowName,
DWORD dwStyle,
RECT& rect,
HWND hParentWnd,
HMENU hMenu,
LPVOID lpParam);
//add the window to WindowManager
void Attach(HWND hwnd);
//remove the window from WindowManager
void Dettach();
//process the WM_CREATE message
virtual int OnCreate(LPCREATESTRUCT ps);
/*
other message function
*/
//process the WM_CREATEMYWINDOW message
virtual void OnCreateMyWindow();
protected:
HWND _hwnd;
HINSTANCE _hInst;
};
MyWindow.cpp中的WindowManager和CBT-HOOK部分
#include "StdAfx.h"
#include "LockEx.h"
#include "MyWindow.h"
//window class name
static TCHAR * _MY_WINDOW_CLASS_NAME_ = L"MYWINDOWCLASS";
//window-proc
LRESULT CALLBACK MyWindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);
///an Mutex-Lock class for keep current hwnd of new window, but you can ignore it when using single thread to crate window
static CLockEx gLockInitWnd;
///keep current hwnd of new window
static CMyWindow * gpInitWnd = 0;
///an hook to create new window
static HHOOK ghook = 0;
///set gpInitWnd when create a new window
static void SetInitWnd(CMyWindow * pWnd)
{
CLockEx::Scoped lock(gLockInitWnd);
gpInitWnd = pWnd;
}
///clear gpInitWnd after new window created
static void UnsetInitWnd()
{
CLockEx::Scoped lock(gLockInitWnd);
gpInitWnd = 0;
}
///get the HWND of new window that is creating
static CMyWindow * GetInitPwnd()
{
CLockEx::Scoped lock(gLockInitWnd);
return gpInitWnd;
}
//CBT-Proc for SetWindowsHookEx
static LRESULT CALLBACK MyCBTProc(int nCode, WPARAM wParam, LPARAM lParam)
{
if (nCode == HCBT_CREATEWND) {
//get the new window from gpInitWnd
CMyWindow * pwnd = GetInitPwnd();
if (pwnd) {
//first time call this proc
//add this window to WindowManager
pwnd->Attach((HWND)wParam);
return (0);
} else {
//sencond time call this proc
CREATESTRUCT * cs = ((CBT_CREATEWND *)lParam)->lpcs;
if (!(cs->style & WS_CHILD)) {
//we can do something here
return (0);
} else {
return (1); //error, destroy the window
//or, maybe, CallNextHookEx
}
}
} else
return CallNextHookEx(ghook, nCode, wParam, lParam);
}
//Create a WH_CBT Hook
static bool HookCrate()
{
HANDLE hThread = GetCurrentThread();
DWORD dwThreadId = GetThreadId(hThread);
if (hThread) {
ghook = SetWindowsHookEx(
WH_CBT,
MyCBTProc, //set the CBT proc
0,
dwThreadId);
if (!ghook)
return false;
}
return (0);
}
//Destroy WH_CBT Hook
static void HookDestroy()
{
if (ghook) {
UnhookWindowsHookEx(ghook);
ghook = 0;
}
}
///////////////////////////////////////////////
//this is a vector for keep all CMyWindow*
CWindowManager::CWindowManager(void)
{
}
CWindowManager::~CWindowManager(void)
{
clear();
}
//insert new window
bool CWindowManager::Add(CMyWindow* pwnd)
{
IterBool ib = insert(WindowPair(pwnd->GetSafeHwnd(), pwnd));
return ib.second;
}
//remove a window by hwnd
bool CWindowManager::Remove(HWND hwnd)
{
WndIterator wi = find(hwnd);
if (wi == end( )) {
return false;
} else {
erase(wi);
return true;
}
}
//find a window by hwnd
CMyWindow* CWindowManager::Find(HWND hwnd)
{
WndIterator wi = find(hwnd);
if (wi == end( )) {
return (0);
} else {
return wi->second;
}
}
//remove all items
void CWindowManager::Clear()
{
clear();
}
//get instance as singleton pattern.
CWindowManager * CWindowManager::GetInstance()
{
static CWindowManager wm;
return &wm;
}
注册窗口类,将WndProc设置为MyWIndowProc
ATOM RegisteWindowClass(HINSTANCE hInstance, TCHAR * szClassName)
{
WNDCLASSEX wcex;
wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = MyWindowProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = 0;
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wcex.lpszMenuName = 0;
wcex.lpszClassName = szClassName;
wcex.hIconSm = 0;
return RegisterClassEx(&wcex);
}
CMyWindow类,请注意我在WM_CREATE和WM_CREATEMYWINDOW消息中的问题
CMyWindow::CMyWindow(void)
: _hwnd(0)
, _hInst(0)
{
}
CMyWindow::~CMyWindow(void)
{
}
inline HWND CMyWindow::GetSafeHwnd()
{
return _hwnd;
}
//Craete a window
bool CMyWindow::Create( HINSTANCE hInstance,
TCHAR * szWindowName,
DWORD dwStyle,
RECT& rect,
HWND hParentWnd,
HMENU hMenu,
LPVOID lpParam)
{
//get safe instance
HINSTANCE hInst = hInstance;
if (!hInstance)
if (!hParentWnd)
return false;
else
hInst = (HINSTANCE) GetWindowLong(hParentWnd, GWL_HINSTANCE);
if (!hInst)
return false;
//register window class
if (!RegisteWindowClass(hInst, _MY_WINDOW_CLASS_NAME_)) {
DWORD dwErr = GetLastError();
if (dwErr != ERROR_CLASS_ALREADY_EXISTS) //0x00000582
return false;
}
//claim i am creating
SetInitWnd(this);
//create CBT hook, then this window will add to WindowManager
HookCrate();
//create window
HWND hwnd = CreateWindow(
_MY_WINDOW_CLASS_NAME_,
szWindowName,
dwStyle,
rect.left, rect.right, rect.right - rect.left, rect.bottom - rect.top,
hParentWnd,
hMenu,
hInstance,
lpParam);
//destroy CBT hook
HookDestroy();
if (!hwnd)
return false;
_hwnd = hwnd;
_hInst = hInst;
//show window
ShowWindow(_hwnd, SW_SHOW);
UpdateWindow(_hwnd);
return true;
}
//add the this window to WindowManager
void CMyWindow::Attach(HWND hwnd)
{
_hwnd = hwnd;
CWindowManager::GetInstance()->Add(this);
UnsetInitWnd();
}
//remove the this window to WindowManager
void CMyWindow::Dettach()
{
CWindowManager::GetInstance()->Remove(_hwnd);
_hwnd = 0;
}
int CMyWindow::OnCreate(LPCREATESTRUCT ps)
{
return (0);
}
void CMyWindow::OnCreateMyWindow()
{
}
//the WndProc callback function
LRESULT CALLBACK MyWindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
//Get the CMyWindow instance from WindowManager by hWnd
CMyWindow * pwnd = CWindowManager::GetInstance()->Find(hWnd);
//can not find thi window in WindowManager
if (!pwnd) return DefWindowProc(hWnd, message, wParam, lParam);
switch (message)
{
case WM_CREATE:
{
//perform the OnCreate function, just like MFC's OnCreate
int r = pwnd->OnCreate(reinterpret_cast<LPCREATESTRUCT>(lParam));
if (r) //some error occurred, will destory the window
return (r);
//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
//I can not create any edit box in OnCreate function,
//I must do it leater, when the window was created and
//WM_CREATEMYWINDOW was received
::PostMessage(hWnd, WM_CREATEMYWINDOW, 0, 0);
}
break;
/*
case WM_.....
other message
case WM_.....
*/
case WM_DESTROY:
::PostQuitMessage(0);
break;
case WM_CREATEMYWINDOW:
//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
//I can not create any edit box in OnCreate function,
//I must do it when WM_CREATEMYWINDOW was received
pwnd->OnCreateMyWindow();
break;
}
return DefWindowProc(hWnd, message, wParam, lParam);
}
现在,继承类CMyWindow来创建两个窗口,第一个窗口将创建第二个带有编辑框的窗口
class CMyWnd2 : public CMyWindow
{
public:
CMyWnd2(void) : _hCmdEdit(0) {}
~CMyWnd2(void){}
protected:
HWND _hCmdEdit;
//create edit box
virtual void OnCreateMyWindow();
};
class CMyWnd1 : public CMyWindow
{
public:
CMyWnd1(void) {}
~CMyWnd1(void){}
protected:
virtual int OnCreate(LPCREATESTRUCT ps);
//create window2
virtual void OnCreateMyWindow();
CMyWnd2 _wnd2;
};
int CMyWnd1::OnCreate(LPCREATESTRUCT /*ps*/)
{
//Can create window2, but can not crate window2's edit-boxs
return (0);
}
//create window2 with edit box
void CMyWnd1::OnCreateMyWindow()
{
RECT rect = {0, 0, 400, 300};
_wnd2.Create(this->_hInst,
0,
WS_VISIBLE | WS_POPUP,
rect,
_hwnd,
0,
0);
}
//create edit box
void CMyWnd2::OnCreateMyWindow()
{
RECT rect;
GetClientRect(_hwnd, &rect);
_hCmdEdit = CreateWindowEx(
WS_EX_STATICEDGE,
L"EDIT",
NULL,
WS_CHILD | WS_VISIBLE | WS_VSCROLL | ES_LEFT | ES_MULTILINE | ES_AUTOVSCROLL,
0,
rect.bottom - 80,
rect.right - rect.left,
80,
_hwnd,
(HMENU) 100,
(HINSTANCE) GetWindowLong(_hwnd, GWL_HINSTANCE),
NULL);
}
最后,WinMain函数创建CMyWnd1的一个实例
CMyWnd1 mainwnd;
RECT rect;
rect.left = rect.top = 0, rect.right = 500, rect.bottom = 400;
mainwnd.Create(hInstance,
L"MyWindow",
WS_OVERLAPPEDWINDOW,
rect,
0,
0,
0);
while (GetMessage(&msg, NULL, 0, 0))
{
if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
这里一定有我错过的东西,有人能帮我解决这个问题吗
请注意,WM_CREATE
消息在CreateWindow()
返回之前发送。这意味着窗口句柄成员_hwnd
(注意:不应使用以_和__开头的标识符,它们是为编译器扩展保留的)尚未初始化,并且包含0。因此,后续的CreateWindow()
调用失败,因为必须传递有效的窗口句柄才能创建子窗口(具有WS_CHILD
样式)。但它是允许弹出窗口(WS_POPUP
风格)。这很可能是创建Wnd2的原因,但编辑框并不是。
我明白了,在CBThook回调函数中发生了一个愚蠢的错误,当第二次调用该函数时,我拒绝了创建WS_CHILD样式窗口的请求。它只需要返回一个零!!请查看评论中的错误。现在它工作了!谢谢罗斯特的提示。
static LRESULT CALLBACK MyCBTProc(int nCode, WPARAM wParam, LPARAM lParam)
{
if (nCode == HCBT_CREATEWND) {
//get the new window from gpInitWnd
CMyWindow * pwnd = GetInitPwnd();
if (pwnd) {
//first time call this proc
//add this window to WindowManager
pwnd->Attach((HWND)wParam);
return (0);
} else {
//sencond time call this proc
return (0);
////
/// below was my stupid code,
////
/*CREATESTRUCT * cs = ((CBT_CREATEWND *)lParam)->lpcs;
if (!(cs->style & WS_CHILD)) {
//we can do something here
return (0);
} else {
return (1); //error, destroy the window
//or, maybe, CallNextHookEx
}*/
}
} else
return CallNextHookEx(ghook, nCode, wParam, lParam);
}
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