01-autorelease基本概念
Person.m
1 #import "Person.h"
2
3 @implementation Person
4
5 - (void)dealloc
6 {
7 [super dealloc];
8 NSLog(@"Person 被销毁了");
9 }
10
11 @end
Person.m
Person.h
1 #import <Foundation/Foundation.h> 2 3 @interface Person : NSObject 4 5 @end
person.h
main.m
1 //内存管理原则(配对原则):只要出现了new,alloc,retain方法,就要配对出现release,autorelease
2 //对象存入到自动释放池中,当这个池子被销毁的时候他会对池子中所有的对象进行一次release操作
3 //怎么把对象存到池子中
4 #import <Foundation/Foundation.h>
5 #import "Person.h"
6
7 int main(int argc, const char * argv[])
8 {
9 /* 示例1
10 //自动释放池
11 //大括号代表池子的作用域
12 @autoreleasepool
13 {
14
15 //release 功能 retaincount - 1
16 //autorelease 好像功能也是 retaincount - 1 ?
17 //1
18 Person * p = [[Person alloc] init];
19 // [p release];//retainCount立即 -1
20 [p autorelease]; //autorelease方法的作用只是将对象放入到池子中,然后返回一个self
21
22 NSLog(@"asdfasdf");
23
24 }//代表,池子将要被销毁,对池子中所有的对象进行一次release操作,[p release] 0
25 */
26
27 /*
28 //autoreleasepool我么可以自己随意的创建
29
30 // 示例2
31 //1//不管你这个对象时在@autoreleasepool 之内创建的还是在之外创建的,只要你在池子中调用了autorelease那么这个对象就会被放入到池子中
32 Person * p = [[Person alloc ] init];
33
34 @autoreleasepool {
35
36 [p autorelease];
37
38 }//p 0
39 */
40 // 示例3
41 /*
42 //1 只有在自动释放池的作用域中调用对象的autorelease方法才能够正确的讲对象放入到池子中
43 Person * p = [[Person alloc] init];
44 [p autorelease];
45
46 NSLog(@"aaaa");
47 @autoreleasepool {
48
49 }
50 NSLog(@"bbb");
51 */
52 //示例4
53 /*
54 // 1
55 Person * p = [[Person alloc] init];
56
57 @autoreleasepool {
58
59 [p autorelease];//加入第一次
60
61 [p autorelease];//加入第二次
62
63 NSLog(@"abc");
64 }//[p release]0 [p release]
65
66 NSLog(@"cbd");
67 */
68
69 //示例5
70 /*
71 //1
72 Person * p = [[Person alloc] init];
73
74 @autoreleasepool {
75
76 @autoreleasepool {
77
78 [p autorelease];
79 }//?[p release] 0
80
81 }
82 */
83
84
85 Person * p = [[Person alloc] init];
86
87 @autoreleasepool {
88
89 [p autorelease];
90
91 @autoreleasepool {
92
93
94 [p autorelease];
95 }//[p release] 0
96
97
98 }//[p release];
99
100
101 return 0;
102 }
main.m
02-autorelease应用
Chief.m
1 #import "Chief.h"
2
3 @implementation Chief
4
5 - (void)dealloc
6 {
7 [super dealloc];
8 NSLog(@"厨师被回收了");
9 }
10
11 + (Chief *)chief
12 {
13 /*
14 Chief * chi = nil;
15
16 chi = [[Chief alloc] init];
17
18 // [chi release];
19 [chi autorelease];
20 */
21
22 Chief * chi = [[self alloc] init];
23
24
25 return [chi autorelease];
26 }
27 - (Food *)chiefMakeFood
28 {
29
30
31 //如果在方法中创建一个对象,最好给我初始化为nil,防止出现野指针错误
32 // 1
33 Food * food = [[Food alloc] init];
34 food.name = @"凑豆乳";
35 // // 0
36 // [food release];
37 [food autorelease];
38
39 return food;
40
41 }
42
43 @end
Chief.m
Chief.h
1 #import <Foundation/Foundation.h> 2 #import "Food.h" 3 4 @interface Chief : NSObject 5 6 + (Chief *)chief; 7 - (Food *)chiefMakeFood; 8 9 @end
Chief.h
Food.m
1 #import "Food.h"
2
3 @implementation Food
4 - (void)dealloc
5 {
6 [super dealloc];
7 [_name release];
8 NSLog(@"Food被销毁了");
9 }
10
11 @end
Food.m
Food.h
1 #import <Foundation/Foundation.h> 2 3 @interface Food : NSObject 4 5 @property(nonatomic,retain) NSString * name; 6 7 @end
Food.h
main.m
1 #import <Foundation/Foundation.h>
2 #import "Chief.h"
3 //autorelease笔试面试出现的几率比[release]
4
5 int main(int argc, const char * argv[])
6 {
7
8 @autoreleasepool {
9
10 /*
11 Chief * chi = [[Chief alloc] init];
12 Food * food = [chi makeFood];;
13
14
15 NSLog(@"%@",food.name);//[nil name];
16
17 [chi release];
18 */
19
20
21
22 Chief * chi = [Chief chief];
23 Food * food = [chi chiefMakeFood];
24
25 NSLog(@"%@",food.name);
26
27 NSString * name = [NSString stringWithFormat:@"%@",@"施瓦辛格"];//都是autorelease
28
29 NSLog(@"%@",name);
30
31 }
32 return 0;
33 }
main.m
03-ARC机制
Person.m
1 #import "Person.h"
2
3 @implementation Person
4
5 - (void)dealloc
6 {
7 // [super dealloc];不能够在调用
8 // releae retain 在ARC机制中不能够在去手动调用
9 NSLog(@"Person 被释放了");
10 }
11
12 @end
Person.m
Person.h
1 #import <Foundation/Foundation.h> 2 3 @interface Person : NSObject 4 5 @end
Person.h
main.m
1 //ARC简单,不用程序员在去管理内存
2 //1.强指针 Strong
3 //2.弱指针 weak
4
5 //只要有强指针指向一个对象,那么系统就不会回收该对象
6 //只要没有强指针指向对象,系统立即回收该对象
7
8 //弱指针不影响,对象被回收
9
10 //默认情况下,所有的指针都是强指针类型
11
12 #import <Foundation/Foundation.h>
13 #import "Person.h"
14
15 void test(Person * v)//Person * v =
16 {
17 v = nil;
18 }//
19
20 int main(int argc, const char * argv[])
21 {
22
23
24
25 /*
26
27 Person * p = [[Person alloc] init];
28
29 // p = nil;
30
31 Person * p1 = p;
32
33 p = nil;
34 */
35
36
37 Person * p = [[Person alloc] init];
38
39 test(p);
40
41 p = nil;
42
43 NSLog(@"adfasdf");
44 /*
45 //创建出来就会立即被释放掉,应为没有强指针指向该对象
46 __weak Person * p = [[Person alloc] init];
47 NSLog(@"adfadf");
48 */
49
50 /*
51 Person * p = [[Person alloc] init];
52
53 __weak Person * p1 = p;
54
55 p = nil;
56 */
57
58
59
60 return 0;
61 }
main.m
04-ARC机制下组合关系
person.m
1 #import "Person.h"
2
3 @implementation Person
4
5 -(void)dealloc
6 {
7 NSLog(@"person 被销毁了");
8 }
9
10 @end
Person.m
Person.h
1 #import <Foundation/Foundation.h> 2 #import "Car.h" 3 4 @interface Person : NSObject 5 6 //@property(nonatomic,retain)Car * car; 7 //ARC机制 strong 对象,手动内存管理的retain关键字,(一定能够都是应用在对象类型变量上) 8 //ARC机制中的 weak 对象手动内存管理的assign关键字,(一定能够都是应用在对象类型变量上) 9 @property (nonatomic,strong)Car * car;//强直阵类型的对象,会影响对象回收 10 @property (nonatomic,weak)Car * car2;// 弱指针类型的对象,不会影响对象的回收 11 //@property (nonatomic,assign)Car * car3;//造成迷惑,会导致许多程序员搞不清这个变量到底是stong类型的还是weak类型 12 13 @property (nonatomic,strong)NSString * name; 14 @property (nonatomic,strong)NSString * idCard; 15 16 //ARC机制下 基本数据类型的@property参数使用,与手动内存管理完全一致 17 @property (nonatomic,assign)int age; 18 19 @end
Person.h
Car.m
1 #import "Car.h"
2
3 @implementation Car
4 - (void)dealloc
5 {
6 NSLog(@"Car 被销毁了");
7 }
8 @end
Car.m
Car.h
1 #import <Foundation/Foundation.h> 2 3 @interface Car : NSObject 4 5 @end
Car.h
main.m
1 #import <Foundation/Foundation.h>
2
3 int main(int argc, const char * argv[])
4 {
5
6 @autoreleasepool {
7
8
9 }
10 return 0;
11 }
main.m
05-手动内存管理转换成ARC机制
Person.m
1 #import "Person.h"
2
3 @implementation Person
4 - (void)dealloc
5 {
6 NSLog(@"PErson 被销毁了");
7 }
8 @end
Person
Person.h
1 #import <Foundation/Foundation.h> 2 3 @interface Person : NSObject 4 5 @property (nonatomic,strong)NSString * name; 6 @property (nonatomic,strong)NSString * idCard; 7 8 @end
Person.h
main.m
1 #import <Foundation/Foundation.h>
2
3 int main(int argc, const char * argv[])
4 {
5
6 @autoreleasepool {
7
8 // insert code here...
9 NSLog(@"Hello, World!");
10
11 }
12 return 0;
13 }
main.m
06-ARC与非ARC共存
Person.m
1 #import "Person.h"
2
3 @implementation Person
4 - (void)sendMessageByIphone:(Iphone *)phone
5 {
6 [phone sendMessageWithNumber:@"123124321"];
7 }
8
9 - (void)dealloc
10 {
11 // [super dealloc];
12 }
13 @end
Person
Person.h
1 #import <Foundation/Foundation.h> 2 #import "Iphone.h" 3 4 @interface Person : NSObject 5 6 - (void)sendMessageByIphone:(Iphone *)phone; 7 8 @end
Person.h
Iphone.m
1 #import "Iphone.h"
2
3 @implementation Iphone
4
5 - (void)dealloc
6 {
7 [super dealloc];
8 [_name release];
9 NSLog(@"Iphone 被销毁了");
10 }
11
12
13 - (void)sendMessageWithNumber:(NSString *)number
14 {
15 NSLog(@"发消息给 %@",number);
16 }
17 @end
Iphone.m
Iphone.h
1 #import <Foundation/Foundation.h> 2 3 @interface Iphone : NSObject 4 5 @property (nonatomic,retain)NSString * name; 6 7 - (void)sendMessageWithNumber:(NSString *)number; 8 9 @end
Iphone.h
main.m
1 #import <Foundation/Foundation.h>
2 #import "Person.h"
3
4 int main(int argc, const char * argv[])
5 {
6
7 @autoreleasepool {
8
9
10
11 }
12 return 0;
13 }
main.m
07-模拟第三方程序
Iphone.m
1 #import "Iphone.h"
2
3 @implementation Iphone
4
5 - (void)dealloc
6 {
7 [super dealloc];
8 [_name release];
9 NSLog(@"Iphone 被销毁了");
10 }
11
12
13 - (void)sendMessageWithNumber:(NSString *)number
14 {
15 NSLog(@"发消息给 %@",number);
16 }
17 @end
Iphone.m
Iphone.h
1 #import <Foundation/Foundation.h> 2 3 @interface Iphone : NSObject 4 5 @property (nonatomic,retain)NSString * name; 6 7 - (void)sendMessageWithNumber:(NSString *)number; 8 9 @end
Iphone.h
main.m
1 #import <Foundation/Foundation.h>
2
3 int main(int argc, const char * argv[])
4 {
5
6 @autoreleasepool {
7
8 // insert code here...
9 NSLog(@"Hello, World!");
10
11 }
12 return 0;
13 }
main.m
08-ARC类循环应用问题
Person.m
1 #import "Person.h"
2
3 @implementation Person
4
5 -(void)dealloc
6 {
7 NSLog(@"Person 被销毁了");
8 }
9
10 @end
Person.m
Person.h
1 #import <Foundation/Foundation.h> 2 #import "Car.h" 3 4 @interface Person : NSObject 5 6 @property (nonatomic,strong)Car * car; 7 8 @end
person.h
Car.m
1 #import "Car.h"
2 #import "Person.h"
3
4 @implementation Car
5
6 - (void)dealloc
7 {
8 NSLog(@"Car 被销毁了");
9 }
10
11 @end
Car.m
Car.h
1 import <Foundation/Foundation.h> 2 //#import "Person.h" 3 @class Person; 4 5 @interface Car : NSObject 6 7 //@property (nonatomic,strong)Person * p; 8 9 //当出现类循环应用的时候,只需要把一方面的Strong引用改为weak,并且在.h文件中使用@class 类名的方式,通知.h文件类的存在 10 @property (nonatomic,weak)Person * p; 11 12 @end
Car.h
main.m
1 #import <Foundation/Foundation.h>
2 #import "Person.h";
3
4 int main(int argc, const char * argv[])
5 {
6
7 @autoreleasepool {
8
9 Person * p = [[Person alloc] init];
10
11 Car * car = [[Car alloc] init];
12
13 [p setCar:car];
14
15 [car setP:p];
16
17 p = nil;
18
19 car = nil;
20
21 NSLog(@"agfadsgf");
22 }
23 return 0;
24 }
main.m
时间： 2024-10-06 12:46:18