wxWidgets学习笔记——在屏幕上画简单的图形和文字

在屏幕上画简单图形和显示图片、处理简单鼠标键盘事件

/***************************************************************

 * Name:      MyApp.h

 * Purpose:   Defines Application Class

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#ifndef WXTESTAPP_H

#define WXTESTAPP_H

#include <wx/app.h>

class MyApp : public wxApp          //应用程序类，应用程序的入口点

{

    public:

        virtual bool OnInit(void);  //在应用程序启动时调用，如果返回false，退出应用程序

};

#endif // WXTESTAPP_H

/***************************************************************

 * Name:      MyApp.cpp

 * Purpose:   Code for Application Class

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#include <wx/wx.h>

//(*AppHeaders

#include "MyApp.h"

#include "MyFrame.h"

//*)

DECLARE_APP(MyApp);

IMPLEMENT_APP(MyApp);

bool MyApp::OnInit(void)

{

    MyFrame * frame = new MyFrame(NULL, wxT("wxWidgets"));    //为新窗口分配空间，设定标题

    frame->Show();

    return wxOK;

}

/***************************************************************

 * Name:      MyFrame.h

 * Purpose:   Defines Application Frame

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#ifndef WXTESTMAIN_H

#define WXTESTMAIN_H

#include <wx/frame.h>

class MyFrame : public wxFrame  //窗体类

{

    public:

        //Constructor

        MyFrame(wxWindow * parent, const wxString & title); //窗体的构造函数

        //Destructor

        ~MyFrame() {};

        //Event handlers

        void OnAbout    (wxCommandEvent & event);

        void OnQuit     (wxCommandEvent & event);

        void OnMotion   (wxMouseEvent   & event);

        void OnPaint    (wxPaintEvent   & event);

        void OnMousePrc (wxMouseEvent   & event);

        void OnKeyPrc   (wxKeyEvent     & event);

    private:

        DECLARE_EVENT_TABLE();

};

#endif // WXTESTMAIN_H

/***************************************************************

 * Name:      MyFrame.cpp

 * Purpose:   Code for Application Frame

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#include <wx/wx.h>

#include <wx/dcbuffer.h>

//(*FrameHeaders

#include "MyApp.h"

#include "MyFrame.h"

#include "wxPingGe.h"

//*)

//事件表：（类，基类）

BEGIN_EVENT_TABLE(MyFrame,wxFrame)

    //(*EventTable(MyFrame)

    EVT_MENU        (wxID_ABOUT,    MyFrame::OnAbout)      //把wxID_ABOUT和OnAbout关联

    EVT_MENU        (wxID_EXIT,     MyFrame::OnQuit)       //把wxID_EXIT和OnQuit关联

    EVT_MOTION      (               MyFrame::OnMotion)     //鼠标事件

    EVT_PAINT       (               MyFrame::OnPaint)      //刷屏消息

    EVT_MOUSE_EVENTS(               MyFrame::OnMousePrc)   //鼠标事件

    EVT_KEY_DOWN    (               MyFrame::OnKeyPrc)     //键盘事件

    //*)

END_EVENT_TABLE()

#include "wx.xpm"

MyFrame::MyFrame(wxWindow * parent, const wxString & title)

       : wxFrame(NULL, wxID_ANY, title)

{

    SetIcon(wxIcon(wx_xpm));

    wxMenu * fileMenu = new wxMenu;             //建立“文件”菜单

    wxMenu * helpMenu = new wxMenu;             //建立“帮助”菜单

    //增加菜单项（标识、文本、帮助字符）

    helpMenu->Append(wxID_ABOUT, wxT("&About...\tF2"),   wxT("Show about dialog"));

    fileMenu->Append(wxID_EXIT,  wxT("&Exit...\tAlt-X"), wxT("Quit this programe"));

    wxMenuBar * menuBar = new wxMenuBar();      //建立一个菜单条

    menuBar->Append(fileMenu, wxT("&File"));    //将"文件"菜单加入到菜单条

    menuBar->Append(helpMenu, wxT("&Help"));    //将“帮助”菜单加入到菜单条

    SetMenuBar(menuBar);                        //将菜单条放到窗体上

    CreateStatusBar();                         //创建两个状态栏，并写上字符串

    SetStatusText(wxT("welcome to wxWidgets!"), );

}

void MyFrame::OnAbout(wxCommandEvent & event)

{

    wxString msg;

    msg.Printf(wxT("hello and welcome to %s"), wxVERSION_STRING);   //消息的字符串

    //消息框：（消息内容、标题、窗口类型、父窗口）

    wxMessageBox(msg, wxT("About Minimal"), wxOK | wxICON_INFORMATION, this);

}

void MyFrame::OnQuit(wxCommandEvent & event)

{

    Close();

}

void MyFrame::OnMotion(wxMouseEvent & event)

{

    if(event.Dragging())                        //鼠标拖动时为真

    {

        wxClientDC dc(this);                    //创建一个指向当前窗口的设备指针dc

        wxPen pen(*wxRED, );                   //创建画笔，颜色：红色，宽度：1

        dc.SetPen(pen);

        dc.DrawPoint(event.GetPosition());      //画点

        dc.SetPen(wxNullPen);

    }

}

void MyFrame::OnPaint(wxPaintEvent & event)     //刷屏消息处理函数

{

    wxBufferedPaintDC mydc(this);

    mydc.SetPen(*wxWHITE_PEN);

    //mydc.SetBrush(*wxRED_BRUSH);

    mydc.SetBrush(wxColor(, , )/*wxRED_BRUSH*/);

    mydc.SetBackground(wxBrush(*wxWHITE, wxSOLID));

    wxSize sz = GetClientSize();                //获取窗口大小

    wxCoord w = , h = ;                    //要绘制的矩形大小

    int x = wxMax(, sz.x / ) - w / ;         //将矩形放置在窗口的正中间，但不为负

    int y = wxMax(, sz.y / ) - h / ;

    wxRect rectToDraw(x, y, w, h);

    if(IsExposed(rectToDraw))                   //只有在需要的时候才重新画以便提高效率

    {

        //mydc.DrawRectangle(rectToDraw);                                 //画矩形

        //DrawTextString(mydc, wxT("test"), wxPoint(50, 50));             //画字符串

        //DrawRotatedTest(mydc, wxT("PingGe"), wxPoint(100, 100), 60);   //旋转字符串

        DrawSimpleShape(mydc);

        DrawMap(mydc);

    }

    /*

    窗口最大化后出现两个矩形，原因是窗口变大时原先部分没有刷新，

    只把新增部分刷新出来；

    */

}

void MyFrame::OnMousePrc(wxMouseEvent & event)

{

    wxPoint pt(event.GetPosition());    //获取当前坐标pt

    wxClientDC dc(this);                //设置一个设备上下文

    if((pt.x > ) && (pt.y > ) && (event.LeftDown()))

    {

        wxPen pen(*wxWHITE, );         //白色画笔

        dc.SetPen(pen);

        dc.DrawLine(, , , );  //当鼠标左键点击位置在(100, 100)之后时用白色画笔画线

    }

    if(event.LeftUp())

    {

        wxPen pen(*wxRED, );           //红色画笔

        dc.SetPen(pen);

        dc.DrawLine(, , , ); //当鼠标左键弹起时，用红色画笔画线

    }

}

void MyFrame::OnKeyPrc(wxKeyEvent & event)  //处理按键按下的消息

{

    wxClientDC dc(this);                    //设置一个设备上下文

    wxPen pen(*wxWHITE, );

    dc.SetPen(pen);                         //白色画笔

    if(event.ShiftDown())                   //按下shift键画一条直线

    {

        dc.DrawLine(, , , );

    }

    int code = event.GetKeyCode();          //获取按下按键的编码

    if(code == )

    {

        dc.DrawLine(, , , );       //当按下A键时画一条直线

    }

}

/***************************************************************

 * Name:      wxPingGe.h

 * Purpose:   Code for Application Frame

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#ifndef _WXPINGGE_H_

#define _WXPINGGE_H_

#include <wx/wx.h>

#include <wx/dcbuffer.h>

//画字符函数：（DC，文本，位置）

void DrawTextString(wxDC & dc, const wxString & text, const wxPoint & pt);

//画旋转字符函数：（DC，文本，位置，旋转角度）

void DrawRotatedTest(wxDC & dc, const wxString & text, const wxPoint & pt, int angle = );

//画一些图形

void DrawSimpleShape(wxDC & dc);

//画图片

void DrawMap(wxDC & dc);

#endif //_WXPINGGE_H_

/***************************************************************

 * Name:      wxPingGe.cpp

 * Purpose:   Code for Application Frame

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#include "wxPingGe.h"

void DrawTextString(wxDC & dc, const wxString & text, const wxPoint & pt)

{

    //定义一个wxFont类的对象font

    //构造函数wxFont::wxFont(字体大小、字体类型(书法、艺术)、斜体)

    wxFont font(, wxFONTFAMILY_SCRIPT, wxNORMAL, wxBOLD);

    //利用DC类的成员函数SetFont设置字体

    dc.SetFont(font);

    //设置背景透或者不透

    dc.SetBackgroundMode(wxSOLID/*wxTRANSPARENT*/);

    //设置前景颜色

    dc.SetTextForeground(*wxRED);

    //设置背景颜色

    dc.SetTextBackground(*wxWHITE);

    //写字，文本wxString，位置wxPoint

    dc.DrawText(text, pt);

}

void DrawRotatedTest(wxDC & dc, const wxString & text, const wxPoint & pt, int angle)

{

    wxFont font(, wxFONTFAMILY_SCRIPT, wxNORMAL, wxBOLD);

    dc.SetFont(font);

    dc.SetBackgroundMode(wxTRANSPARENT/*wxSOLID*/);

    dc.SetTextForeground(*wxWHITE);

    dc.SetTextBackground(*wxRED);

    dc.DrawRotatedText(text, pt, angle);

}

void DrawSimpleShape(wxDC & dc)

{

    //设置画笔画刷

    dc.SetPen(wxPen(*wxRED, , wxSOLID));

    dc.SetBrush(wxBrush(*wxGREEN, wxSOLID));

    //画抛物线

    dc.DrawSpline(, , , , , );

    //画点

    dc.DrawPoint(, );

    //画线：（注意，最后一个点不会画）

    dc.DrawLine(, , , );

    //画矩形：（用画笔画边框，画刷填充内部）

    dc.DrawRectangle(, , , );

    //设置画刷为红色

    dc.SetBrush(*wxRED_BRUSH);

    //画圆角矩形

    dc.DrawRoundedRectangle(, , , , );

    //设置颜色

    dc.SetBrush(wxColor(, , ));

    //画圆

    dc.DrawCircle(, , );

}

#include "1.xpm"

void DrawMap(wxDC & dc)

{

    wxBitmap bitmap(logo_xpm);

    dc.DrawBitmap(bitmap, , , wxBITMAP_TYPE_XPM);

    dc.SetTextBackground(*wxBLACK);

    dc.SetTextForeground(*wxWHITE);

    wxString msg = wxT("Some text is mixed in bmp shade.");

    for(int i = , step = ; i < ; i++, step += )

    {

        dc.DrawText(msg, , step);

    }

}

在屏幕上画普通文字和旋转的文字

/***************************************************************

 * Name:      MyApp.h

 * Purpose:   Defines Application Class

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#ifndef WXTESTAPP_H

#define WXTESTAPP_H

#include <wx/app.h>

class MyApp : public wxApp          //应用程序类，应用程序的入口点

{

    public:

        virtual bool OnInit(void);  //在应用程序启动时调用，如果返回false，退出应用程序

};

#endif // WXTESTAPP_H

/***************************************************************

 * Name:      MyApp.cpp

 * Purpose:   Code for Application Class

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#include <wx/wx.h>

//(*AppHeaders

#include "MyApp.h"

#include "MyFrame.h"

//*)

DECLARE_APP(MyApp);

IMPLEMENT_APP(MyApp);

bool MyApp::OnInit(void)

{

    MyFrame * frame = new MyFrame(NULL, wxT("wxWidgets"));    //为新窗口分配空间，设定标题

    frame->Show();

    return wxOK;

}

/***************************************************************

 * Name:      MyFrame.h

 * Purpose:   Defines Application Frame

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#ifndef WXTESTMAIN_H

#define WXTESTMAIN_H

#include <wx/frame.h>

class MyFrame : public wxFrame  //窗体类

{

    public:

        //Constructor

        MyFrame(wxWindow * parent, const wxString & title); //窗体的构造函数

        //Destructor

        ~MyFrame() {};

        //Event handlers

        void OnAbout    (wxCommandEvent & event);

        void OnQuit     (wxCommandEvent & event);

        void OnMotion   (wxMouseEvent   & event);

        void OnPaint    (wxPaintEvent   & event);

    private:

        DECLARE_EVENT_TABLE();

};

#endif // WXTESTMAIN_H

/***************************************************************

 * Name:      MyFrame.cpp

 * Purpose:   Code for Application Frame

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#include <wx/wx.h>

#include <wx/dcbuffer.h>

//(*FrameHeaders

#include "MyApp.h"

#include "MyFrame.h"

#include "wxPingGe.h"

//*)

//事件表：（类，基类）

BEGIN_EVENT_TABLE(MyFrame,wxFrame)

    //(*EventTable(MyFrame)

    EVT_MENU    (wxID_ABOUT, MyFrame::OnAbout)

    EVT_MENU    (wxID_EXIT,  MyFrame::OnQuit)

    EVT_MOTION  (            MyFrame::OnMotion)

    EVT_PAINT   (            MyFrame::OnPaint)

    //*)

END_EVENT_TABLE()

#include "wx.xpm"

MyFrame::MyFrame(wxWindow * parent, const wxString & title)

       : wxFrame(NULL, wxID_ANY, title)

{

    SetIcon(wxIcon(wx_xpm));

    wxMenu * fileMenu = new wxMenu;             //建立“文件”菜单

    wxMenu * helpMenu = new wxMenu;             //建立“帮助”菜单

    //增加菜单项（标识、文本、帮助字符）

    helpMenu->Append(wxID_ABOUT, wxT("&About...\tF2"),   wxT("Show about dialog"));

    fileMenu->Append(wxID_EXIT,  wxT("&Exit...\tAlt-X"), wxT("Quit this programe"));

    wxMenuBar * menuBar = new wxMenuBar();      //建立一个菜单条

    menuBar->Append(fileMenu, wxT("&File"));    //将"文件"菜单加入到菜单条

    menuBar->Append(helpMenu, wxT("&Help"));    //将“帮助”菜单加入到菜单条

    SetMenuBar(menuBar);                        //将菜单条放到窗体上

    CreateStatusBar();                         //创建两个状态栏，并写上字符串

    SetStatusText(wxT("welcome to wxWidgets!"));

}

void MyFrame::OnAbout(wxCommandEvent & event)

{

    wxString msg;

    msg.Printf(wxT("hello and welcome to %s"), wxVERSION_STRING);   //消息的字符串

    //消息框：（消息内容、标题、窗口类型、父窗口）

    wxMessageBox(msg, wxT("About Minimal"), wxOK | wxICON_INFORMATION, this);

}

void MyFrame::OnQuit(wxCommandEvent & event)

{

    Close();

}

void MyFrame::OnMotion(wxMouseEvent & event)

{

    if(event.Dragging())                        //鼠标拖动时为真

    {

        wxClientDC dc(this);                    //创建一个指向当前窗口的设备指针dc

        wxPen pen(*wxRED, );                   //创建画笔，颜色：红色，宽度：1

        dc.SetPen(pen);

        dc.DrawPoint(event.GetPosition());      //画点

        dc.SetPen(wxNullPen);

    }

}

void MyFrame::OnPaint(wxPaintEvent & event)     //刷屏消息处理函数

{

    wxBufferedPaintDC mydc(this);

    mydc.SetPen(*wxBLACK_PEN);

    mydc.SetBrush(*wxRED_BRUSH);

    wxSize sz = GetClientSize();                //获取窗口大小

    wxCoord w = , h = ;                    //要绘制的矩形大小

    int x = wxMax(, sz.x / ) - w / ;         //将矩形放置在窗口的正中间，但不为负

    int y = wxMax(, sz.y / ) - h / ;

    wxRect rectToDraw(x, y, w, h);

    if(IsExposed(rectToDraw))                   //只有在需要的时候才重新画以便提高效率

    {

        mydc.DrawRectangle(rectToDraw);

        DrawTextString(mydc, wxT("test"), wxPoint(, ));             //画字符串

        DrawRotatedTest(mydc, wxT("PingGe"), wxPoint(, ), );    //旋转字符串

    }

    /*

    窗口最大化后出现两个矩形，原因是窗口变大时原先部分没有刷新，

    只把新增部分刷新出来；

    */

}

/***************************************************************

 * Name:      wxPingGe.h

 * Purpose:   Code for Application Frame

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#ifndef _WXPINGGE_H_

#define _WXPINGGE_H_

#include <wx/wx.h>

#include <wx/dcbuffer.h>

//画字符函数：（DC，文本，位置）

void DrawTextString(wxDC & dc, const wxString & text, const wxPoint & pt);

//画旋转字符函数：（DC，文本，位置，旋转角度）

void DrawRotatedTest(wxDC & dc, const wxString & text, const wxPoint & pt, int angle = );

#endif //_WXPINGGE_H_

/***************************************************************

 * Name:      wxPingGe.cpp

 * Purpose:   Code for Application Frame

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#include "wxPingGe.h"

void DrawTextString(wxDC & dc, const wxString & text, const wxPoint & pt)

{

    //定义一个wxFont类的对象font

    //构造函数wxFont::wxFont(字体大小、字体类型(书法、艺术)、斜体)

    wxFont font(, wxFONTFAMILY_SCRIPT, wxNORMAL, wxBOLD);

    //利用DC类的成员函数SetFont设置字体

    dc.SetFont(font);

    //设置背景透或者不透

    dc.SetBackgroundMode(wxSOLID/*wxTRANSPARENT*/);

    //设置前景颜色

    dc.SetTextForeground(*wxRED);

    //设置背景颜色

    dc.SetTextBackground(*wxWHITE);

    //写字，文本wxString，位置wxPoint

    dc.DrawText(text, pt);

}

void DrawRotatedTest(wxDC & dc, const wxString & text, const wxPoint & pt, int angle)

{

    wxFont font(, wxFONTFAMILY_SCRIPT, wxNORMAL, wxBOLD);

    dc.SetFont(font);

    dc.SetBackgroundMode(wxTRANSPARENT/*wxSOLID*/);

    dc.SetTextForeground(*wxWHITE);

    dc.SetTextBackground(*wxRED);

    dc.DrawRotatedText(text, pt, angle);

}

在屏幕上画点和矩形

/***************************************************************

 * Name:      MyApp.h

 * Purpose:   Defines Application Class

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#ifndef WXTESTAPP_H

#define WXTESTAPP_H

#include <wx/app.h>

class MyApp : public wxApp

{

    public:

        virtual bool OnInit(void);

};

#endif // WXTESTAPP_H

/***************************************************************

 * Name:      MyApp.cpp

 * Purpose:   Code for Application Class

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#include "MyApp.h"

//(*AppHeaders

#include "wx/wx.h"

#include "MyFrame.h"

//*)

DECLARE_APP(MyApp);

IMPLEMENT_APP(MyApp);

bool MyApp::OnInit(void)

{

    MyFrame * frame = new MyFrame(NULL, wxT("wxWidgets"));    //为新窗口分配空间，设定标题

    frame->Show();

    return wxOK;

}

/***************************************************************

 * Name:      MyFrame.h

 * Purpose:   Defines Application Frame

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#ifndef WXTESTMAIN_H

#define WXTESTMAIN_H

#include <wx/frame.h>

class MyFrame : public wxFrame

{

    public:

        //Constructor

        MyFrame(wxWindow * parent, const wxString & title);

        //Destructor

        ~MyFrame() {};

        //Event handlers

        void OnAbout    (wxCommandEvent & event);

        void OnQuit     (wxCommandEvent & event);

        void OnMotion   (wxMouseEvent   & event);

        void OnPaint    (wxPaintEvent   & event);

    private:

        DECLARE_EVENT_TABLE();

};

#endif // WXTESTMAIN_H

/***************************************************************

 * Name:      MyFrame.cpp

 * Purpose:   Code for Application Frame

 * Author:    PingGe ([email protected])

 * Created:   2013-10-14

 * Copyright: PingGe (http://www.cnblogs.com/pingge/)

 * License:

 **************************************************************/

#include "MyFrame.h"

//(*InternalHeaders(wxTestDialog)

#include "wx/wx.h"

#include "wx/dcbuffer.h"

#include "MyApp.h"

//*)

BEGIN_EVENT_TABLE(MyFrame,wxFrame)

    //(*EventTable(wxTestDialog)

    EVT_MENU    (wxID_ABOUT, MyFrame::OnAbout)

    EVT_MENU    (wxID_EXIT,  MyFrame::OnQuit)

    EVT_MOTION  (            MyFrame::OnMotion)

    EVT_PAINT   (            MyFrame::OnPaint)

    //*)

END_EVENT_TABLE()

#include "wx.xpm"

MyFrame::MyFrame(wxWindow * parent, const wxString & title)

       : wxFrame(NULL, wxID_ANY, title)

{

    SetIcon(wxIcon(wx_xpm));

    wxMenu * fileMenu = new wxMenu;             //定义两个菜单项

    wxMenu * helpMenu = new wxMenu;

    //增加菜单项（标识、文本、帮助字符）

    helpMenu->Append(wxID_ABOUT, wxT("&About...\tF2"),   wxT("Show about dialog"));

    fileMenu->Append(wxID_EXIT,  wxT("&Exit...\tAlt-X"), wxT("Quit this programe"));

    wxMenuBar * menuBar = new wxMenuBar();      //定义菜单条

    menuBar->Append(fileMenu, wxT("&File"));

    menuBar->Append(helpMenu, wxT("&Help"));

    SetMenuBar(menuBar);

    CreateStatusBar();                         //创建两个状态栏，并写上字符串

    SetStatusText(wxT("welcome to wxWidgets!"));

}

void MyFrame::OnAbout(wxCommandEvent & event)

{

    wxString msg;

    msg.Printf(wxT("hello and welcome to %s"), wxVERSION_STRING);   //消息的字符串

    //消息框：（消息内容、标题、窗口类型、父窗口）

    wxMessageBox(msg, wxT("About Minimal"), wxOK | wxICON_INFORMATION, this);

}

void MyFrame::OnQuit(wxCommandEvent & event)

{

    Close();

}

void MyFrame::OnMotion(wxMouseEvent & event)

{

    if(event.Dragging())    //鼠标拖动时为真

    {

        wxClientDC dc(this);    //创建一个指向当前窗口的设备指针dc

        wxPen pen(*wxRED, );   //创建画笔，颜色：红色，宽度：1

        dc.SetPen(pen);

        dc.DrawPoint(event.GetPosition());

        dc.SetPen(wxNullPen);

    }

}

void MyFrame::OnPaint(wxPaintEvent & event)

{

    wxBufferedPaintDC mydc(this);

    mydc.SetPen(*wxBLACK_PEN);

    mydc.SetBrush(*wxRED_BRUSH);

    wxSize sz = GetClientSize();    //获取窗口大小

    wxCoord w = , h = ;        //要绘制的矩形大小

    int x = wxMax(, sz.x / ) - w / ;     //将矩形放置在窗口的正中间，但不为负

    int y = wxMax(, sz.y / ) - h / ;

    wxRect rectToDraw(x, y, w, h);

    if(IsExposed(rectToDraw))       //只有在需要的时候才重新画以便提高效率

    {

        mydc.DrawRectangle(rectToDraw);

    }

    /*

    窗口最大化后出现两个矩形，原因是窗口变大时原先部分没有刷新，

    只把新增部分刷新出来；

    */

}