MFC SDI动态创建按钮

Question

我正在尝试动态创建一个按钮。我已阅读其他一些资源并制作以下​​代码：

BEGIN_MESSAGE_MAP(Cdynamic_button_sdiView, CView)
    // Standard printing commands
    ON_BN_CLICKED(MYBUTTONID, OnMyBN_Click)
END_MESSAGE_MAP()
void Cdynamic_button_sdiView::OnInitialUpdate()
{
    CView::OnInitialUpdate();
    m_Button.Create(_T("Rearrange"), WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON, CRect(0, 0, 128, 32), this, MYBUTTONID); // here will create a button
}

启动MFC应用程序时，我可以成功创建一个按钮。问题是当我尝试通过点击打开新文档时：

我收到错误，我的应用程序在m_Button.Create(_T("Rearrange"), WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON, CRect(0, 0, 128, 32), this, MYBUTTONID);时崩溃了

Answer 1

我用以下代码解决了问题：

Cdynamic_button_sdiView::Cdynamic_button_sdiView()
{
    // TODO: add construction code here
    m_Button = NULL;
}

Cdynamic_button_sdiView::~Cdynamic_button_sdiView()
{
    if (m_Button != NULL)
        delete m_Button;
}
void Cdynamic_button_sdiView::OnInitialUpdate()
{
    CView::OnInitialUpdate();

    if (m_Button != NULL)
        delete m_Button;

    m_Button = new CButton;
    m_Button->Create(_T("Rearrange"), WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON, CRect(0, 0, 128, 32), this, MYBUTTONID); // here will create a button
}

可能是问题是我不应该在OnInitialUpdate（）里面重新创建窗口