结构体

location = 定位到那里
length = 长度

@”I love oc”
location = 2
length = 4
// 表示love 的所在位置
NSRange range = NSMakeRange(2, 4);

NSString *str =@”I love oc”;
// 在str 中找love字符串的范围
// 如果找不到length = 0 ；location = NSNotFound = -1
NSRange r = [str rangeOfString:@"love"];

1、 NSPoint \ CGPoint 点
NSPoint point = NSMakePoint(20,20);
CGPoint point2 = CGPointMake(20,20);

2、 NSSize \ CGSize 尺寸
NSSize size = NSMakeSize(100,50);
CGSize size2 = CGSizeMake(100,50);

3、 NSRect \ CGRect 矩形
NSRect rect = NSMakeRect(0, 0, 100, 50);
CGRect rect2 = CGRectMake(0, 0, 100, 50);

坐标原点
CGPointZero == CGPointMake(0,0)
CGPointZero == CGSizeMake(0,0)
CGPointZero == CGPointMake(0,0)

// 比较2个(point，rect，size)是否相同
// 比较2个(point)是否相同
BOOL b = CGPointEqualToPoint(CGPointMake(0,0), CGPointMake(1,0));

// 比较2个(size)是否相同
BOOL b = CGPointEqualToSize(CGSizeMake(0,0), CGSizeMake(1,0));

// 比较2个(rect)是否相同
BOOL b = CGPointEqualToRect(CGRectMake(0,0,0,0), CGRectMake(1,5,1,2));