Basic Methods of object oriented programming (MFC)

Not to mention directly accessing the code

#pragma onceclass Shape{public:Shape(void){}virtual ~Shape(void){}virtual void Draw(CDC *pDC) = 0;void SetRect(int left, int top, int right, int bottom){m_rc.SetRect(left, top, right, bottom);}void offest(int x, int y){m_rc.OffsetRect(x, y);}protected:CRect m_rc;};class CCircle :public Shape{public:CCircle(void){}~CCircle(void){}virtual void Draw(CDC *pDC){pDC->Ellipse(m_rc);}};class CSquare :public Shape{public:CSquare(void){}~CSquare(void){}virtual void Draw(CDC *pDC){pDC->Rectangle(m_rc);}};class CRoundSquare :public Shape{public:CRoundSquare(void){}~CRoundSquare(void){}virtual void Draw(CDC *pDC){POINT pt = { 10, 10 };pDC->RoundRect(m_rc, pt);}};

Picture

How to draw

Where to draw

In this example

protected:CArray<Shape*, Shape*> m_Shape;

The advantage of using pointers is that you can perform the following operations:

m_Shape.Add(new CCircle());m_Shape.Add(new CSquare());m_Shape.Add(new CRoundSquare());

The above method can be used for reference. We have a lot of objects inherited from different classes of the same class.

Before a class is instantiated, all operations are abstracted to itself (data) possible operations may involve some possible methods, such as drawing a rectangle and moving it. So what this class can do is to use any desired class to implement its own objective class. data is actually details

When getting an object, you can operate on it, that is, develop on the basis of the most primitive class object, call the member function, make this object full, in this case, many local parameters are obtained as real parameters of class functions.

This is like an animal, which has many subjects and genetic characteristics. When it comes to every animal, we will know its characteristics in detail.

The world is complicated. When we use all our resources to achieve our purpose, our purpose is achieved. We think everything is done.

In fact, our class is probably a handler for other classes to achieve their goals.

Mutual reference between classes constitutes a complete program

The interaction of all people in the world constitutes this society.

The top class and instance should exist in the program, such as the app class in MFC.

Followed by the program management system computer and then human

But humans are definitely not the ultimate goal or there is a higher category than humans.

They don't care about us, humans, that is, we humans, but they're just a tiny child in their eyes.

Haha think too much ............