wxwidgets在panel上添加控件不成功

问题描述:

if(NULL == ActiveUserFrame)
{
 //*********创建UserManageFrame***************
 ActiveUserFrame = new wxMiniFrame(this, wxID_ANY, "当前用户信息", wxDefaultPosition, wxSize(800,550));
wxPanel *m_panel = new wxPanel(ActiveUserFrame);
}

wxButton *m_button = new wxButton(m_panel, -1);

如上代码控件m_button添加到m_panel上失败.

改为下面就行,原因不明:

 ActiveUserFrame = new wxMiniFrame(this, wxID_ANY, "当前用户信息", wxDefaultPosition, wxSize(800,550));
wxPanel *m_panel = new wxPanel(ActiveUserFrame);

wxButton *m_button = new wxButton(m_panel, -1);