矩形和区域

下面有三个绘图函数需要一个指向矩形结构的指针：

FillRect(hdc,&rect,hbursh);//填充

FrameRect(hdc,&rect,hbrush);//掏空

InvertRect(hdc,&rect);//内部取反

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

            //hrgn=CreateRectRgn(100,100,300,300);
            //hbrush=CreateSolidBrush(RGB(255,0,0));
            //FillRgn(hdc,hrgn,hbrush);
            //InvertRgn(hdc,hrgn);//取反
            //FrameRgn(hdc,hrgn,hbrush,0,0);


            r1.left=100;
            r1.top=100;
            r1.right=200;
            r1.bottom=200;
            hbrush=CreateSolidBrush(RGB(255,0,0));//创建画刷
            FillRect(hdc,&r1,hbrush);

            r2.left=200;
            r2.top=100;
            r2.right=300;
            r2.bottom=200;
            FrameRect(hdc,&r2,hbrush);

            r3.left=300;
            r3.top=100;
            r3.right=400;
            r3.bottom=200;
            InvertRect(hdc,&r3);

            EndPaint(hwnd,&ps);
            return 0;

下面还有八个关于矩形的操作：

OffsetRect(&rect,x,y)	将矩形移动
InflateRect(&rect,x,y)	增大缩小矩形的尺寸
SetRectEmpty(&rect)	把矩形结构各字段设置为0
CopyRect(&DestRect,&ScrRect)	将一个矩形结构复制到另一个矩形结构
IntersectRect(&destRect,&SrcRect1,&SrcRect2)	获取两个矩形的交集
UnionRect(&DestRect,&SrcRect1,&SrcRect2)	获取两个矩形的并集
bEmpty=IsRectEmpty(&Rect)	判断矩形是否为空
bInRect=PtInRect(&rect,point)	判断点是否在矩形内部

 

区域跟矩形一样，有以下四个绘图函数

FillRgn(hdc,hrgn,hbrush);
FrameRgn(hdc,hbrush,xFrame,yFrame);
InvertRgn(hdc,hrgn);
PaintRgn(hdc,hrgn);

DeleteObject(hrgn);

SelectObject(hdc,hrgn)=SelectClipRgn(hdc,hrgn);

使得矩形，区域有效和无效的函数

InvalidateRect       ValidateRect
InvalidateRgn        ValidateRgn

下面是简单的例子：

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

            //hrgn=CreateRectRgn(100,100,300,300);
            //hbrush=CreateSolidBrush(RGB(255,0,0));
            //FillRgn(hdc,hrgn,hbrush);
            //InvertRgn(hdc,hrgn);//取反
            //FrameRgn(hdc,hrgn,hbrush,0,0);


            r1.left=100;
            r1.top=100;
            r1.right=200;
            r1.bottom=200;
            hbrush=CreateSolidBrush(RGB(255,0,0));//创建画刷
            //FillRect(hdc,&r1,hbrush);

            r2.left=150;
            r2.top=100;
            r2.right=250;
            r2.bottom=200;
            //FrameRect(hdc,&r2,hbrush);

            IntersectRect(&r3,&r1,&r2);//r1,r2矩形取交集，存放在r3
            FillRect(hdc,&r3,hbrush);
            flag=(int)IsRectEmpty(&r3);//判断矩形是否为空
            TextOut(hdc,300,300,szBuffer,wsprintf(szBuffer,TEXT("%d"),flag));

            EndPaint(hwnd,&ps);
            return 0;

hrgn=CreateRectRgn(xleft,ytop,xright,ybottom);
hrgn=CreateRectRgnIndirect(&rect);
hrgn=CreateEllipticRgn(xleft,ytop,xright,ybottom);
hrgn=CreatePolygonRgn(&point,icount,ipolyFillMode);