Using the CFileDialog Class Directly

CFileDialog dlg(TRUE, "bmp", "*.bmp");
if (dlg.DoModal() == IDOK) {
    CFile file;
    VERIFY(file.Open(dlg.GetPathName(), CFile::modeRead));
}

The first constructor parameter (TRUE) specifies that this object is a
"File Open" dialog instead of a "File Save" dialog. The default file extension
is bmp, and *.bmp appears first in the filename edit box. The
CFileDialog::GetPathName function returns a CString object that
contains the full pathname of the selected file.

Nested Dialogs

我们可以自己定制一个资源模板，让Common Dialog寄宿在我们的模板里：

1.Run AppWizard to produce \vcpp32\ex07b\ex07b. Accept all the defaults but
two: select Single Document and deselect Printing And Print Preview. The options
and the default class names are shown in the next graphic.
用向导生成一个工程ex07b，去掉打印功能。

2.Use the dialog editor to create a dialog resource.
Make the dialog box about
3-by-5 inches, and use the ID IDD_FILESPECIAL. Set the dialog’s Style
property to Child, its Border property to None, and select its Clip Siblings and
Visible properties. Create the template with a button with ID IDC_DELETE
and a group box with ID stc32=0×045f, as shown here.
在资源中插入一个Dialog，设置其ID为IDD_FILESPECIAL，并将属性改为Child窗体，边框设为None，选上Siblings。在上面画一个GroupBox，ID设为stc32=0×045f，去掉Visible。再画一个Button with ID IDC_DELETE

Check your work by choosing Resource Symbols from the Visual C++ View menu.
You should see a symbol list like the one shown in the graphic below.
在View菜单下面检查一下资源的ID是否正确。

3.Use ClassWizard to create the CSpecialFileDialog class. Fill in the
New Class dialog, as shown here, and then click the Change button.
用向导生成类CSpecialFileDialog，Change the names to SpecFileDlg.h and SpecFileDlg.cpp.

Unfortunately, we cannot
use the Base Class drop-down list to change the base class to
CFileDialog, as that would decouple our class from the
IDD_FILESPECIAL template. We have to change the base class by hand.

4.Map the WM_INITDIALOG message in the CSpecialDialog class. The
OnInitDialog member function needs to change the common dialog’s Open
button caption to Delete. The child window ID is IDOK.

BOOL bRet = CFileDialog::OnInitDialog();
if (bRet == TRUE) {
    GetParent()->GetDlgItem(IDOK)->SetWindowText("Delete");
}
return bRet;

5.Map the new IDC_DELETE button (Delete All Matching Files) in the
CSpecialDialog class. 

 void CSpecialFileDialog::OnDelete() 
{
    m_bDeleteAll = TRUE;
    // 0x480 is the child window ID of the File Name edit control
    //  (as determined by SPYXX)
    GetParent()->GetDlgItem(0x480)->GetWindowText(m_strFilename);
    GetParent()->SendMessage(WM_COMMAND, IDCANCEL);
}

The OnDelete member function sets the
m_bDeleteAll flag and then forces the main dialog to exit as if the
Cancel button had been clicked. The client program (in this case, the view) gets
the IDCANCEL return from DoModal and reads the flag to see whether
it should delete all files. Here is the function:


6.Edit the file SpecFileDlg.h.
1)change
class CSpecialFileDialog : public CDialog
to
class CSpecialFileDialog : public CFileDialog

2)Add the following two public data members:

CString m_strFilename;
BOOL m_bDeleteAll;

3)Finally, edit the constructor declaration:

CSpecialFileDialog(BOOL bOpenFileDialog, 
    LPCTSTR lpszDefExt = NULL,
    LPCTSTR lpszFileName = NULL,
    DWORD dwFlags = OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,
    LPCTSTR lpszFilter = NULL,
    CWnd* pParentWnd = NULL
);

7.Edit the CSpecialFileDialog constructor in SpecFileDlg.cpp. 

CSpecialFileDialog::CSpecialFileDialog(BOOL bOpenFileDialog,
        LPCTSTR lpszDefExt, LPCTSTR lpszFileName, DWORD dwFlags,
        LPCTSTR lpszFilter, CWnd* pParentWnd)
    : CFileDialog(bOpenFileDialog, lpszDefExt, lpszFileName,
        dwFlags, lpszFilter, pParentWnd)
{
    //{{AFX_DATA_INIT(CSpecialFileDialog)
        // NOTE: the ClassWizard will add member initialization here
    //}}AFX_DATA_INIT
    m_ofn.Flags |= OFN_ENABLETEMPLATE;
    m_ofn.lpTemplateName = MAKEINTRESOURCE(IDD_FILESPECIAL);
    m_ofn.lpstrTitle = "Delete File";
    m_bDeleteAll = FALSE;
}


In addition, it must set some members of the CFileDialog base class data 
member m_ofn, which is an instance of the Win32 OPENFILENAME 
structure. The Flags and lpTemplateName members control the 
coupling to your IDD_FILESPECIAL template, and the lpstrTitle 
member changes the main dialog box title.

8.Replace CDialog with CFileDialog in SpecFileDlg.h And SpecFileDlg.cpp

9.Add code to the virtual OnDraw function in file ex07bView.cpp. The 
CEx07bView OnDraw function (whose skeleton was generated by AppWizard) 
should be coded as follows to prompt the user to press the mouse button: 

10.Add the OnLButtonDown message handler to the CEx07bView class. Use
ClassWizard to create the message handler for WM_LBUTTON-DOWN, and then edit the
code as follows:

void CEx07bView::OnLButtonDown(UINT nFlags, CPoint point) 
{
    CSpecialFileDialog dlgFile(TRUE, NULL, "*.obj");
    CString strMessage;
    int nModal = dlgFile.DoModal();
    if ((nModal == IDCANCEL) && (dlgFile.m_bDeleteAll)) {
        strMessage.Format(
            "Are you sure you want to delete all %s files?",
            dlgFile.m_strFilename);
        if (AfxMessageBox(strMessage, MB_YESNO) == IDYES) {
            HANDLE h;
            WIN32_FIND_DATA fData;
            while((h = ::FindFirstFile(dlgFile.m_strFilename, &fData))
                    != (HANDLE) 0xFFFFFFFF) { // no MFC equivalent
                if (::DeleteFile(fData.cFileName) == FALSE) {
                    strMessage.Format("Unable to delete file %s\n",
                        fData.cFileName);
                    AfxMessageBox(strMessage);
                    break;
                }
            }
        }
    }
    else if (nModal == IDOK) {
        CString strSingleFilename = dlgFile.GetPathName();
        strMessage.Format(
            "Are you sure you want to delete %s?", strSingleFilename);
        if (AfxMessageBox(strMessage, MB_YESNO) == IDYES) {
            CFile::Remove(strSingleFilename);
        }
    }
}

11.Of course, you'll need to include the statement