NSRange (location length)
"I love oc"
NSRange r = NSMakeRange（2，4）
NSString *str = @"i love you";
NSRange range = [str rangeofString:@"love"];
NSLog(@"loc = %ld, length = %ld",range.location, range.length);
找不到length = 0，location = NSNotFound == -1（涉及符号位）
NSPointCGPoint 跨平台
CGPoint p = NSMakePoint(10, 10);
NSPoint p = CGPointMake(20, 20);
CGSize s = NSMakeSize(20, 20);
NSSize s = CGSizeMake(100,100);
NSRectCGRect(CGPoint CGSize)
CGRect r = CGRectMake(0, 0, 2, 3);
origin.x
origin.y
sieze.width
sieze.height
NSLog("%@",[NSStringFromeSize(s)]);
NSStringFromeRect(r)
CGPointZero == CGPointMake(0, 0)
CGRect r1 = {CGPointZero, CGSizeMake(100, 100)};
BOOL b = CGPointEqualToPoint(CGPointMake(10, 10), CGPointMake(10, 20));
CGRectEqualToRect
BOOL b = CGRectContainsPoint(CGRectMake(40, 50, 60, 70), CGPointMake(80, 80));
CG = CoreGraphics框架
NS = NextStep 的 Foundation