1、查找某个字符串在str中的范围 (使用 rangeOfString:@"")
1 #import <Foundation/Foundation.h>
2 //查找某个字符串在str中的范围
3 void test()
4 {
5 NSString *str = @"i love you";
6 NSRange range = [str rangeOfString:@"ov"];
7 //如果找不到：length = 0, location = NSNotFound = -1
8 NSRange range1 = [str rangeOfString:@"good"];
9 NSLog(@"ov.location = %ld, ov.length = %ld", range.location, range.length);
10 //这里location使用%d输出,结果就是-1
11 NSLog(@"good.location = %ld, good.length = %ld", range1.location, range1.length);
12 }
13 int main(int argc, const char * argv[])
14 {
15 test();
16 return 0;
17 }
输出结果：
2、CGRect结构体变量的赋值
1 #import <Foundation/Foundation.h>
2 void test()
3 {
4 CGPoint p1 = CGPointMake(10, 10);
5 CGPoint p2 = CGPointMake(20, 20);
6 CGSize s1 = CGSizeMake(100, 50);
7 CGSize s2 = CGSizeMake(200, 80);
8
9 CGRect r1 = CGRectMake(0, 0, 100, 50);
10 CGRect r2 = {{0, 0}, {100, 50}};
11 // 在给CGRect变量赋值时，可以直接使用CGPoint变量和CGSize变量
12 CGRect r3 = {p1, s2};
13 NSString *str = NSStringFromRect(r3);
14 NSLog(@"%@", str);
15 }
16 int main(int argc, const char * argv[])
17 {
18 test();
19 return 0;
20 }
当出现第10行这种情况：CGRect r2 = {{0, 0}, {100, 50}}; point坐标为{0, 0}的时候，可以使用CGPointZero来替换。CGPointZero表示的是坐标原点(x==0, y==0)。
代码：
1 void test1()
2 {
3 CGRect r1 = {{0, 0}, {100, 80}};
4 CGRect r2 = {CGPointZero, {100, 80}};
5
6 NSString *str1 = NSStringFromRect(r1);
7 NSString *str2 = NSStringFromRect(r2);
8 NSLog(@"%@", str1);
9 NSLog(@"%@", str2);
10 }
11 int main(int argc, const char * argv[])
12 {
13 test1();
14 return 0;
15 }
同理，size坐标为{0, 0}等价于CGSizeZero。
综上可知：CGPointZero == CGPointMake(0, 0); 表示坐标原点
CGSizeZero == CGSizeMake(0, 0); 表示尺寸为0
CGRectZero == CGRectMake(0, 0, 0, 0);
3、利用BOOL CGPointEqualToPoint(CGPoint point1, CGPoint point2) 判断两个点是否是同一个点
代码：
1 #import <Foundation/Foundation.h>
2
3 int main(int argc, const char * argv[])
4 {
5 CGPoint point1 = CGPointMake(10, 10);
6 CGPoint point2 = CGPointMake(10, 10);
7 CGPoint point3 = CGPointMake(10, 20);
8 int a = CGPointEqualToPoint(point1, point2);
9 int b = CGPointEqualToPoint(point1, point3);
10 NSLog(@"a = %d", a);
11 NSLog(@"b = %d", b);
12 return 0;
13 }
由函数CGPointEqualToPoint(CGPoint point1, CGPoint point2); 可以推知以下函数：
CGSizeEqualToSize(CGSize size1, CGSize size2); 判断两个尺寸是否相同
CGRectEqualToRect(CGRect rect1, CGRect rect2);
4、利用CGRectContainsPoint(CGRect rect, CGPoint point); 判断一个点是否在一个区域内
1 //判断一个点是否在一个区域内
2 void test1()
3 {
4 CGRect rect = CGRectMake(40, 30, 100, 50);
5 CGPoint point = CGPointMake(50, 45);
6 int s = CGRectContainsPoint(rect, point);
7 NSLog(@"s = %d", s);
8 }
9 int main(int argc, const char * argv[])
10 {
11 test1();
12 return 0;
13 }
