绘图 ios (CGRect Frame Bounds)

1.CGRectOffset

origin源点沿着x轴和y轴偏移offset

数据结构为

CGRect CGRectOffset(        CGRect rect,         CGFloat dx,         CGFloat dy);

举个栗子

float offset = 125.0;    CGRect r1 = CGRectMake(100, 100, 5, 5);    CGRect r2 = CGRectOffset(r1, offset, offset);        NSLog(@"%f %f %f %f",r2.origin.x,r2.origin.y,r2.size.width,r2.size.height);    //225.000000 225.000000 5.000000 5.000000

2.CGRectInset

数据结构为

CGRect CGRectInset (   CGRect rect,   CGFloat dx,   CGFloat dy);

比之原来的矩形放大或者缩小dx，dy像素，负数为放大，正数为缩小