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);
