《windows程序设计》- 图形基础 - sinewave - MFC版

其实不用处理WM_SIZE消息，但是为了练习，加上了：
头文件：

class CMyApp : public CWinApp {
    virtual BOOL InitInstance();
};

class CMainWindow : public CFrameWnd {
public:
    CMainWindow();
protected:
    static const int num = 1000;
    POINT pt[num];
    int cxClient, cyClient;
    afx_msg void OnSize(UINT nType, int cx, int cy);
    afx_msg void OnPaint();
    DECLARE_MESSAGE_MAP()
};

cpp:

#include <afxwin.h>
#include <math.h>
#include "sina.h"

CMyApp myApp;

BOOL CMyApp::InitInstance() {
    m_pMainWnd = new CMainWindow;
    m_pMainWnd->ShowWindow(m_nCmdShow);
    m_pMainWnd->UpdateWindow();
    return TRUE;
}

BEGIN_MESSAGE_MAP(CMainWindow, CFrameWnd)
    ON_WM_SIZE()
    ON_WM_PAINT()
END_MESSAGE_MAP()

CMainWindow::CMainWindow() {
    Create(NULL, "看我来画正弦曲线曲线曲线!");
}

void CMainWindow::OnSize(UINT nType,
                         int cx,
                         int cy) {
                             cxClient = cx;
                             cyClient = cy;
}
void CMainWindow::OnPaint() {
    CPaintDC dc(this);
    dc.MoveTo(0, cyClient / 2);
    dc.LineTo(cxClient, cyClient / 2);
    for(int i = 0; i < num; i++) {
        pt[i].x = i * cxClient / num;
        pt[i].y = cyClient / 2 - (cyClient / 2) * sin(2 * 3.14159 * i / num);
    }
    dc.Polyline(pt, num);
}

运行结果：