Question

VC++(MFC)实现直角坐标系的输出

Answer 1

void CTestDlg::OnButtonDraw()
{
DrawCoordinate(CPoint(100,250), 200, 6, 150, 10);
}

// 顶点坐标, x轴长度, x轴刻度数(含原点), y轴长度, y轴刻度数(含原点)
void CTestDlg::DrawCoordinate(CPoint point, int xLen, int xNum, int yLen, int yNum)
{
int x = xLen + 5;
int y = yLen + 5;

CDC *pDC = GetDC();
pDC->SetBkMode(TRANSPARENT); // 设置透明
pDC->MoveTo(point);
pDC->LineTo(CPoint(point.x+x, point.y)); // 绘制x轴
pDC->MoveTo(point);
pDC->LineTo(CPoint(point.x, point.y-y)); // 绘制y轴
pDC->TextOut(point.x-5, point.y+5, _T("0"));
pDC->TextOut(point.x+x+20, point.y-5, _T("X"));
pDC->TextOut(point.x-5, point.y-y-20, _T("Y"));

// 计算刻度宽度
int x_width = xLen / xNum;
int y_width = yLen / yNum;
int x_pixel = 0; // 当前x坐标
int y_pixel = 0; // 当前y坐标

for(int i=0; i<xNum; i++)
{
x_pixel = i*x_width;
pDC->MoveTo(CPoint(point.x+x_pixel, point.y-2)); // 绘制x轴刻度
pDC->LineTo(CPoint(point.x+x_pixel, point.y+4));

if(i > 0)
{
CString str;
str.Format(_T("%d"), i);
pDC->TextOut(point.x+x_pixel-2, point.y+3, str);
}
}

for(int j=0; j<yNum; j++)
{
y_pixel = j*y_width;
pDC->MoveTo(CPoint(point.x-2, point.y-y_pixel)); // 绘制y轴刻度
pDC->LineTo(CPoint(point.x+4, point.y-y_pixel));

if(j > 0)
{
CString str;
str.Format(_T("%d"), j);
pDC->TextOut(point.x-15, point.y-y_pixel-6, str);
}
}

ReleaseDC(pDC);
}

当然你也可以通过定义POINT数组，数组中记录每个点的坐标，接着使用CDC的PolyLineTo或PolyLine等多边形函数进行线段描绘，效果一样，看你喜欢哪种了

Answer 2

DrawCoordinate(CPoint(100,250), 200, 6, 150, 10);
}

// 顶点坐标, x轴长度, x轴刻度数(含原点), y轴长度, y轴刻度数(含原点)
void CTestDlg::DrawCoordinate(CPoint point, int xLen, int xNum, int yLen, int yNum)
{
int x = xLen + 5;
int y = yLen + 5;

CDC *pDC = GetDC();
pDC->SetBkMode(TRANSPARENT); // 设置透明
pDC->MoveTo(point);
pDC->LineTo(CPoint(point.x+x, point.y)); // 绘制x轴
pDC->MoveTo(point);
pDC->LineTo(CPoint(point.x, point.y-y)); // 绘制y轴
pDC->TextOut(point.x-5, point.y+5, _T("0"));
pDC->TextOut(point.x+x+20, point.y-5, _T("X"));
pDC->TextOut(point.x-5, point.y-y-20, _T("Y"));

// 计算刻度宽度
int x_width = xLen / xNum;
int y_width = yLen / yNum;
int x_pixel = 0; // 当前x坐标
int y_pixel = 0; // 当前y坐标

for(int i=0; i<xNum; i++)
{
x_pixel = i*x_width;
pDC->MoveTo(CPoint(point.x+x_pixel, point.y-2)); // 绘制x轴刻度
pDC->LineTo(CPoint(point.x+x_pixel, point.y+4));

if(i > 0)
{
CString str;
str.Format(_T("%d"), i);
pDC->TextOut(point.x+x_pixel-2, point.y+3, str);
}
}

for(int j=0; j<yNum; j++)
{
y_pixel = j*y_width;
pDC->MoveTo(CPoint(point.x-2, point.y-y_pixel)); // 绘制y轴刻度
pDC->LineTo(CPoint(point.x+4, point.y-y_pixel));

if(j > 0)
{
CString str;
str.Format(_T("%d"), j);
pDC->TextOut(point.x-15, point.y-y_pixel-6, str);
}
}

ReleaseDC(pDC);
}

Answer 3

用画线的方法，输出
比如一个箭头就画三条线

Answer 4

有一个setpitch的指令，你可以搜索一下