程序入口点在哪里

时间:2014-10-14 09:46:57

标签: c++ visual-c++

我有使用exWidgets的简单Windows窗体应用程序。通过查看这种使用表单和面向对象编程的程序,我总是有疑问 - 程序入口点在哪里? main在哪里?

#include "wx/wx.h" 

class MyApp: public wxApp
{
    virtual bool OnInit();
};

class MyFrame: public wxFrame
{
public:

    MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size);

    void OnQuit(wxCommandEvent& event);
    void OnAbout(wxCommandEvent& event);

    DECLARE_EVENT_TABLE()
};

enum
{
    ID_Quit = 1,
    ID_About,
};

BEGIN_EVENT_TABLE(MyFrame, wxFrame)
    EVT_MENU(ID_Quit, MyFrame::OnQuit)
    EVT_MENU(ID_About, MyFrame::OnAbout)
END_EVENT_TABLE()

IMPLEMENT_APP(MyApp)

bool MyApp::OnInit()
{
    MyFrame *frame = new MyFrame( "Hello World", wxPoint(50,50), wxSize(450,340) );
    frame->Show(TRUE);
    SetTopWindow(frame);
    return TRUE;
} 

MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size)
: wxFrame((wxFrame *)NULL, -1, title, pos, size)
{
    wxMenu *menuFile = new wxMenu;

    menuFile->Append( ID_About, "&About..." );
    menuFile->AppendSeparator();
    menuFile->Append( ID_Quit, "E&xit" );

    wxMenuBar *menuBar = new wxMenuBar;
    menuBar->Append( menuFile, "&File" );

    SetMenuBar( menuBar );

    CreateStatusBar();
    SetStatusText( "Welcome to wxWindows!" );
}

void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
{
    Close(TRUE);
}

void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
{
    wxMessageBox("This is a wxWindows Hello world sample",
        "About Hello World", wxOK | wxICON_INFORMATION, this);
}

1 个答案:

答案 0 :(得分:1)

入口点在

IMPLEMENT_APP(MyApp)