我得到了以下兩個CDialog類,它們是用於從模板和從CDialog中取消的類CMainDialog創建對話框窗口,並且有一些方法可以操作對話框上的控件。不知何故,類的成員更改
class CDialog
{
public:
CDialog(DWORD dwTemplate) : m_dwTemplateID(dwTemplate), m_hWnd(NULL) {};
virtual ~CDialog() {};
static INT_PTR CALLBACK DialogProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
virtual BOOL Create(HINSTANCE hInstance, HWND hParent = NULL);
BOOL Show(BOOL bShow);
private:
DWORD m_dwTemplateID;
protected:
HWND m_hWnd;
virtual INT_PTR HandleMessages(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
};
//基地對話框實現
#include "BaseDialog.h"
//statics
INT_PTR CALLBACK Inc::CDialog::DialogProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
Inc::CDialog* pDialog = nullptr;
if(uMsg == WM_INITDIALOG)
{
//save address of the CDialog-object into the dialog´s userdata
pDialog = (Inc::CDialog*)lParam;
SetWindowLongPtr(hWnd, GWLP_USERDATA, (LONG_PTR)pDialog);
}
else
{
//get the pointer
pDialog = (Inc::CDialog*)GetWindowLongPtr(hWnd, GWLP_USERDATA);
}
if(pDialog)
{
//handle messages
return pDialog->HandleMessages(hWnd, uMsg, wParam, lParam);
}
return FALSE; //!pDialog
}
INT_PTR Inc::CDialog::HandleMessages(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch(uMsg)
{
case WM_CLOSE:
DestroyWindow(m_hWnd);
return TRUE;
case WM_DESTROY:
PostQuitMessage(0);
return TRUE;
};
return FALSE; //Message not handled => system will take action
}
BOOL Inc::CDialog::Create(HINSTANCE hInstance, HWND hParent)
{
m_hWnd = CreateDialogParam(hInstance, MAKEINTRESOURCE(m_dwTemplateID), hParent, DialogProc, (LPARAM)this);
if(m_hWnd == NULL)
return FALSE;
return TRUE;
}
//return values: TRUE => window was previously visible, FALSE otherwise
BOOL Inc::CDialog::Show(BOOL bShow)
{
if(bShow)
return ShowWindow(m_hWnd, SW_SHOWNORMAL);
return ShowWindow(m_hWnd, SW_HIDE);
}
// CMainDialog
class CMainDialog :
public Inc::CDialog
{
public:
CMainDialog(DWORD dwTemplateID);
virtual ~CMainDialog(void);
virtual INT_PTR HandleMessages(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
private:
static const char m_szDates[8][14];
//Dialog control item
HWND m_hDateComboBox;
HWND m_hItemListBox;
HWND m_hDescriptionEditBox;
HWND m_hButtonClose;
HWND m_hButtonSave;
HWND m_hButtonDelete;
//get save the control item handles
public:
void GetControlHandles();
public:
void PopulateDateComboBox();
};
// CMAIN對話實現
#include "MainDialog.h"
#include <WindowsX.h>
#include "resource.h"
#include <stdexcept>
//statics
const char Inc::CMainDialog::m_szDates[8][14] = {"Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday", "Single Event"};
Inc::CMainDialog::CMainDialog(DWORD dwTemplateID) : CDialog(dwTemplateID)
{
}
Inc::CMainDialog::~CMainDialog(void)
{
}
//adds the entries in m_szDates to the Combo Box for choosing the date
void Inc::CMainDialog::PopulateDateComboBox()
{
for(unsigned short s = 0; s < 8; s++)
{
if(ComboBox_AddString(m_hDateComboBox, m_szDates[s]) <= CB_ERR)
throw(std::runtime_error("ComboBox_AddString() failed"));
}
}
INT_PTR Inc::CMainDialog::HandleMessages(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch(uMsg)
{
case WM_INITDIALOG:
this->GetControlHandles(); // It happens here !!!!!!! <====
this->PopulateDateComboBox();
return TRUE;
}
return Inc::CDialog::HandleMessages(hWnd, uMsg, wParam, lParam); //if message isnt handled here, default handling
}
void Inc::CMainDialog::GetControlHandles()
{
//Get Control window handles
m_hDateComboBox = GetDlgItem(m_hWnd, IDC_COMBO_DAY);
m_hItemListBox = GetDlgItem(m_hWnd, IDC_LIST);
m_hDescriptionEditBox = GetDlgItem(m_hWnd, IDC_EDIT_DESCRIPTION);
m_hButtonClose = GetDlgItem(m_hWnd, IDC_BUTTON_CLOSE);
m_hButtonSave = GetDlgItem(m_hWnd, IDC_BUTTON_SAVE_CHANGE);
m_hButtonDelete = GetDlgItem(m_hWnd, IDC_BUTTON_DELETE_ITEM);
}
的問題,我確實遇到是,在個CMainDialog :: HandleMessages()當WM_INITDIALOG應該處理的m_hWnd成員成員函數NULL甚至壽CDialog的:創建()功能確實成功和窗口句柄返回m_hWnd。
的CDialog的:DialogProc-過程似乎是在去上班的路上,它得到從WM_INITDIALOG的LPARAM正確的地址,讓pDialog終場指向正確的對象和呼叫it's成員函數。
也許你看到我錯過了什麼或者我做錯了什麼。
預先感謝您調用CreateDialog期間處理