Question

VC中CRect类的简介

我想知道所有有关CRect类的简介。包括成员函数，成员变量。还有派生类的成员变量成员函数。谢谢了。

Answer 1

类CRect是对Windows结构RECT的封装，凡是能用RECT结构的地方都可以用CRect代替。
结构RECT表示一个矩形的位置和尺寸，其定义为：
typedef struct tagRECT{
LONG left;
LONG top;
LONG right;
LONG bottom;
} RECT;
其中 left、top分别表示矩形左上角顶点的横坐标和纵坐标，right、bottom分别表示矩形右下角顶点的横坐标和纵坐标。由于CRect提供了一些成员函数和重载运算符，使得CRect的操作更加方便。 1．CRect的构造函数 CRect有如下6个构造函数：
CRect（ ）;
CRect（ int l, int t, int r, int b ）;
CRect（ const RECT& srcRect ）;
CRect（ LPCRECT lpSrcRect ）;
CRect（ POINT point, SIZE size ）;
CRect（ POINT topLeft, POINT bottomRight ）;
说明：分别以不同的方式构造CRect对象，参数l，t，r，b分别指定矩形的左边、上边、右边和底边。SrcRect是一个RECT结构的引用。LpSrcRect是一个指向RECT结构的指针。Point指定矩形的左上角顶点的坐标，size指定矩形的长度和宽度。topLeft指定矩形的左上角顶点的坐标，bottomRight指定矩形的右下角顶点的坐标。

Answer 2

CRec类是MFC的一个类，用于记录一个矩形的位置以及对矩形的相关操作

Answer 3

//Microsoft Visual Studio\VC98\Include\wtypes.h中
typedef struct tagRECT
{
LONG left;
LONG top;
LONG right;
LONG bottom;
} RECT;

//Microsoft Visual Studio\VC98\MFC\Include\afxwin.h中
class CRect : public tagRECT
{
public:

// Constructors

// uninitialized rectangle
CRect();
// from left, top, right, and bottom
CRect(int l, int t, int r, int b);
// copy constructor
CRect(const RECT& srcRect);
// from a pointer to another rect
CRect(LPCRECT lpSrcRect);
// from a point and size
CRect(POINT point, SIZE size);
// from two points
CRect(POINT topLeft, POINT bottomRight);

// Attributes (in addition to RECT members)

// retrieves the width
int Width() const;
// returns the height
int Height() const;
// returns the size
CSize Size() const;
// reference to the top-left point
CPoint& TopLeft();
// reference to the bottom-right point
CPoint& BottomRight();
// const reference to the top-left point
const CPoint& TopLeft() const;
// const reference to the bottom-right point
const CPoint& BottomRight() const;
// the geometric center point of the rectangle
CPoint CenterPoint() const;
// swap the left and right
void SwapLeftRight();
static void SwapLeftRight(LPRECT lpRect);

// convert between CRect and LPRECT/LPCRECT (no need for &)
operator LPRECT();
operator LPCRECT() const;

// returns TRUE if rectangle has no area
BOOL IsRectEmpty() const;
// returns TRUE if rectangle is at (0,0) and has no area
BOOL IsRectNull() const;
// returns TRUE if point is within rectangle
BOOL PtInRect(POINT point) const;

// Operations

// set rectangle from left, top, right, and bottom
void SetRect(int x1, int y1, int x2, int y2);
void SetRect(POINT topLeft, POINT bottomRight);
// empty the rectangle
void SetRectEmpty();
// copy from another rectangle
void CopyRect(LPCRECT lpSrcRect);
// TRUE if exactly the same as another rectangle
BOOL EqualRect(LPCRECT lpRect) const;

// inflate rectangle's width and height without
// moving its top or left
void InflateRect(int x, int y);
void InflateRect(SIZE size);
void InflateRect(LPCRECT lpRect);
void InflateRect(int l, int t, int r, int b);
// deflate the rectangle's width and height without
// moving its top or left
void DeflateRect(int x, int y);
void DeflateRect(SIZE size);
void DeflateRect(LPCRECT lpRect);
void DeflateRect(int l, int t, int r, int b);

// translate the rectangle by moving its top and left
void OffsetRect(int x, int y);
void OffsetRect(SIZE size);
void OffsetRect(POINT point);
void NormalizeRect();

// set this rectangle to intersection of two others
BOOL IntersectRect(LPCRECT lpRect1, LPCRECT lpRect2);

// set this rectangle to bounding union of two others
BOOL UnionRect(LPCRECT lpRect1, LPCRECT lpRect2);

// set this rectangle to minimum of two others
BOOL SubtractRect(LPCRECT lpRectSrc1, LPCRECT lpRectSrc2);

// Additional Operations
void operator=(const RECT& srcRect);
BOOL operator==(const RECT& rect) const;
BOOL operator!=(const RECT& rect) const;
void operator+=(POINT point);
void operator+=(SIZE size);
void operator+=(LPCRECT lpRect);
void operator-=(POINT point);
void operator-=(SIZE size);
void operator-=(LPCRECT lpRect);
void operator&=(const RECT& rect);
void operator|=(const RECT& rect);

// Operators returning CRect values
CRect operator+(POINT point) const;
CRect operator-(POINT point) const;
CRect operator+(LPCRECT lpRect) const;
CRect operator+(SIZE size) const;
CRect operator-(SIZE size) const;
CRect operator-(LPCRECT lpRect) const;
CRect operator&(const RECT& rect2) const;
CRect operator|(const RECT& rect2) const;
CRect MulDiv(int nMultiplier, int nDivisor) const;
};

可以搜索到具体的实现，