Question

我试图将CFileDialog和IFileOpenDialog包装在一个类中，这是代码：

class ITest
{
    public:
    virtual ~ITest(){};

    virtual INT_PTR DoModal() = 0;

    virtual IFileOpenDialog* GetDlg() = 0;
};

class test : public ITest
{
public:
   test(BOOL bOpenFileDialog, // TRUE for FileOpen, FALSE for FileSaveAs
       LPCTSTR lpszDefExt = NULL,
       LPCTSTR lpszFileName = NULL,
       DWORD dwFlags = OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,
       LPCTSTR lpszFilter = NULL,
       CWnd* pParentWnd = NULL,
       DWORD dwSize = 0,
       BOOL bVistaStyle = FALSE)
   {
       dlg = new CFileDialog(bOpenFileDialog, lpszDefExt, lpszFileName, dwFlags, lpszFilter, pParentWnd, dwSize, bVistaStyle);
   };
   ~test(){};

   INT_PTR DoModal(){ return S_OK; };

   IFileOpenDialog* GetDlg(){ return dlg->GetIFileOpenDialog(); };
private:
   CFileDialog* dlg;
};

然后当我称之为：

ITest* a = new test(TRUE, NULL, 0, OFN_ALLOWMULTISELECT | OFN_NOVALIDATE, LoadResourceString(IDS_MYSTRING), this);

fdlg = a->GetDlg();

fdlg->Show(NULL);//it crashes here since fdlg is NULL

然后我尝试直接致电CFileDialog和IFileOpenDialog：

IFileOpenDialog* fdlg = NULL;

CFileDialog* b = new CFileDialog(TRUE, NULL, 0, OFN_ALLOWMULTISELECT | OFN_NOVALIDATE, LoadResourceString(IDS_MYSTRING), this);

fdlg = b->GetIFileOpenDialog();

fdlg->Show(NULL);

这部分代码完美无缺。谁知道崩溃发生的原因？这让我很困惑，因为我觉得它们非常相似。

class test : public ITest
{
public:
test(BOOL bOpenFileDialog, // TRUE for FileOpen, FALSE for FileSaveAs
    LPCTSTR lpszDefExt = NULL,
    LPCTSTR lpszFileName = NULL,
    DWORD dwFlags = OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,
    LPCTSTR lpszFilter = NULL,
    CWnd* pParentWnd = NULL,
    DWORD dwSize = 0,
    BOOL bVistaStyle = FALSE)
{
    dlg = new CFileDialog(bOpenFileDialog, lpszDefExt, lpszFileName, dwFlags, lpszFilter, pParentWnd, dwSize, bVistaStyle);
};
~test(){};

INT_PTR DoModal(){ return S_OK; };

IFileOpenDialog* GetDlg();
private:
CFileDialog* dlg;
};

IFileOpenDialog* test::GetDlg()
{ 
return dlg->GetIFileOpenDialog(); 
};

上面的代码也行不通（它定义了IFileOpenDialog * GetDlg（）;在类声明之外）

Answer 1

来自help：

仅在具有对象的Windows Vista下使用此功能 bVistaStyle设置为true。如果CFileDialog，此函数返回NULL 不是“打开”对话框，或者如果bVistaStyle设置为false。

构建test对象时：

ITest* a = new test(TRUE, NULL, 0, OFN_ALLOWMULTISELECT | OFN_NOVALIDATE, LoadResourceString(IDS_MYSTRING), this);

您要离开构造函数的最后一个参数bVistaStyle，默认为FALSE。所以只需添加它：

ITest* a = new test(TRUE, NULL, 0, OFN_ALLOWMULTISELECT | OFN_NOVALIDATE, LoadResourceString(IDS_MYSTRING), this, 0, 
               TRUE); // bVistaStyle

从CFileDialog调用时，IFileOpenDialog指针为null

1 个答案: