考试问题，大家帮帮忙

[bonn]

要在屏幕建立一个窗口，然后窗口里显示一个坐标系包括X,Y轴，还有一个正弦函数曲线，考试上机题目，大家棒棒忙啊

[bonn]

老师要的是用MFC写的，而且要有坐标系的，要有箭头

[jackwuwei]

这个画了坐标，但不是余旋曲线，自己画一下

CString str;
LONG i;
LONG max;
CPaintDC dc(this); // device context for painting
CWnd *pWnd=GetDlgItem(IDC_COORD);
CDC *pDC=pWnd->GetDC();
pWnd->Invalidate();
pWnd->UpdateWindow();
pDC->Rectangle(0,0,330,300);
CPen* pPenRed=new CPen;
pPenRed->CreatePen(PS_SOLID,1,RGB(255,0,0));
CPen* pPenBlue=new CPen;
pPenBlue->CreatePen(PS_SOLID,1,RGB(0,0,255));
CPen* pPenGreen=new CPen;
pPenGreen->CreatePen(PS_DOT,1,RGB(0,255,0));
CGdiObject* pOld=pDC->SelectObject(pPenRed);
pDC->MoveTo(10,10);
pDC->LineTo(10,280);
pDC->LineTo(320,280);
str.Format("0");
pDC->TextOut(10,283,str);
str.Format("50");
pDC->TextOut(60,283,str);
str.Format("100");
pDC->TextOut(110,283,str);
str.Format("150");
pDC->TextOut(160,283,str);
str.Format("200");
pDC->TextOut(210,283,str);
str.Format("255");
pDC->TextOut(265,283,str);
for(i=0;i<256;i+=5)
{
if((i&1)==0)
{
pDC->MoveTo(i+10,280);
pDC->MoveTo(i+10,284);
}
else
{
pDC->MoveTo(i+10,280);
pDC->LineTo(i+10,282);
}
}
pDC->MoveTo(315,275);
pDC->LineTo(320,280);
pDC->LineTo(315,285);

pDC->MoveTo(10,10);
pDC->LineTo(5,15);
pDC->MoveTo(10,10);
pDC->LineTo(15,15);
for(i=m_iLow;i<=m_iUp;i++)
{
if(m_lCount[i]>max)
{
max=m_lCount[i];
}
}
pDC->MoveTo(10,25);
pDC->LineTo(14,25);
str.Format("%d",max);
pDC->TextOut(11,26,str);
pDC->SelectObject(pPenGreen);
pDC->MoveTo(m_iLow+10,25);
pDC->LineTo(m_iLow+10,280);

pDC->MoveTo(m_iUp+10,25);
pDC->LineTo(m_iUp+10,280);

pDC->SelectObject(pPenBlue);
if(max>0)
{
for(i=m_iLow;i<=m_iUp;i++)
{
pDC->MoveTo(i+10,280);
pDC->LineTo(i+10,281-(int)(m_lCount[i]*256/max));
}
}
pDC->SelectObject(pOld);
delete pPenRed;
delete pPenBlue;
delete pPenGreen;

[bonn]

hoho,我自己看了伙书，终于会了，谢谢各位大虾的帮忙，会我考完就给大家

[keiven]

呵呵，恭喜楼主！

[GR]

windows程序设计。第五章，5.2完整的程序，精彩的讲解。

[byry]

void CTestView::OnDraw(CDC* pDC)
{
CTestDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
// TODO: add draw code for native data here

pDC->MoveTo(10,120);
pDC->LineTo(400, 120);
pDC->MoveTo(20, 10);
pDC->LineTo(20, 230);

for(int i=20; i<381; i++)
{
float a,b;
a = sinf((float)(i-20)/180*3.14159265)*100.0;
b = sinf((float)(i-19)/180*3.14159265)*100.0;
pDC->MoveTo(i, (int)a+120);
pDC->LineTo(i+1, (int)b+120);
}
}

[sxslyy]

程式5-2 SINEWAVE
SINEWAVE.C
/*-------------------------------------------------------------------
SINEWAVE.C -- Sine Wave Using Polyline
(c) Charles Petzold, 1998
---------------------------------------------------------------------*/
#include <windows.h>
#include <math.h>

#define NUM 1000
#define TWOPI (2 * 3.14159)
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain ( HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("SineWave") ;
HWND hwnd ;
MSG msg ;
WNDCLASS wndclass ;

wndclass.style = CS_HREDRAW | CS_VREDRAW ;
wndclass.lpfnWndProc= WndProc ;
wndclass.cbClsExtra = 0 ;
wndclass.cbWndExtra = 0 ;
wndclass.hInstance = hInstance ;
wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;
wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;
wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
wndclass.lpszMenuName = NULL ;
wndclass.lpszClassName = szAppName ;

if (!RegisterClass (&wndclass))
{
MessageBox ( NULL, TEXT ("Program requires Windows NT!"),
szAppName, MB_ICONERROR) ;
return 0 ;
}

hwnd = CreateWindow ( szAppName, TEXT ("Sine Wave Using Polyline"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL) ;
ShowWindow (hwnd, iCmdShow) ;
UpdateWindow (hwnd) ;

while (GetMessage (&msg, NULL, 0, 0))
{
TranslateMessage (&msg) ;
DispatchMessage (&msg) ;
}
return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static int cxClient, cyClient ;
HDC hdc ;
int i ;
PAINTSTRUCT ps ;
POINT apt [NUM] ;

switch (message)
{
case WM_SIZE:
cxClient = LOWORD (lParam) ;
cyClient = HIWORD (lParam) ;
return 0 ;

case WM_PAINT:
hdc = BeginPaint (hwnd, &ps) ;

MoveToEx (hdc, 0, cyClient / 2, NULL) ;
LineTo (hdc, cxClient, cyClient / 2) ;

for (i = 0 ; i < NUM ; i++)
{
apt[i].x = i * cxClient / NUM ;
apt[i].y = (int) (cyClient / 2 * (1 - sin (TWOPI * i / NUM))) ;
}

Polyline (hdc, apt, NUM) ;
return 0 ;

case WM_DESTROY:
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}

[sxslyy]

主要是这段:
MoveToEx (hdc, 0, cyClient / 2, NULL) ;
LineTo (hdc, cxClient, cyClient / 2) ;

for (i = 0 ; i < NUM ; i++)
{
apt[i].x = i * cxClient / NUM ;
apt[i].y = (int) (cyClient / 2 * (1 - sin (TWOPI * i / NUM))) ;
}

Polyline (hdc, apt, NUM) ;
return 0 ;

[Jasonn]

up

[PiggyXP]

不错，收藏一个

[Kudeet]

1月分的帖子顶起来了啊！



收藏

[lianglp]

呵呵，一楼真行

[nineclock]

呵呵，一楼真行

[niky8053]

这么多答案，

[broown]

楼主也把你的代码，帖出来看看

[一生有爱1980]

都不错，收藏