iOS开发——实用技术OC篇&各种传值方式总结

单例
//.h
 1 + (Instannce *)shareInstance; 
//.m

 1 static Instannce *instance = nil;
 2 @implementation Instannce
 3 //定义一个创建单例对象的方法
 4 + (Instannce *)shareInstance {
 5     if (instance == nil) {
 6         instance = [[Instannce alloc] init];
 7     }
 8     return instance;
 9 }
10 //使用alloc的时候调用的方法instancetype
11 + (id)allocWithZone:(struct _NSZone *)zone {
12     if (instance == nil) {
13         instance = [super allocWithZone:zone];
14     }
15     return instance;
16 }
17 - (id)copy {
18     return self;
19 }
20 - (id)retain {
21     return self;
22 }
23 - (NSUInteger)retainCount {
24     //返回无符号最大值
25     return UINT_MAX;
26 }
27 - (oneway void)release {
28     //什么也不做
29 }

 代理
//.h

1 @protocol GetMessageProtocol <NSObject >
2 - (void)getNum:(NSString *)num withPassWord:(NSString *)pass;
3 @end
4 @property (nonatomic,assign) id<GetMessageProtocol> delegate;

//.m

1 if ([self.delegate respondsToSelector:@selector(getNum:withPassWord:)]) {
2         [self.delegate getNum:num.text withPassWord:passWord.text];
3     }
4 #pragma mark - GetMessageProtocol
5 - (void)getNum:(NSString *)num withPassWord:(NSString *)pass {
6
7 }
8 registerCtrl.delegate = self;

 通知 注意postNotificationName 必须一致

1  [[NSNotificationCenter defaultCenter] postNotificationName:NotificationName object:self userInfo:dic];  //dic存放在userinfo中   dic中存放要传过去的值是个字典
2 //接受通知
3     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changeAction:) name:NotificationName object:nil];

 KVO监听

 1  keyPath: 监听的属性名
 2  object： 被观察的对象
 3  change: 属性值
 4  context: 上下设备文
 5
 6     [registerCtrl addObserver:self forKeyPath:@"属性名称1" options:NSKeyValueObservingOptionNew|NSKeyValueObservingOptionOld context:nil];
 7     [registerCtrl addObserver:self forKeyPath:@"属性名称2" options:NSKeyValueObservingOptionNew context:nil];
 8 //触发的事件
 9 - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
10     //object的值是registerCtrl
11     if ([keyPath isEqualToString:@"属性名称1"]) {
12
13     }else if ([keyPath isEqualToString:@"属性名称2"]) {
14
15     }
16 }

KVO观察者方法

//.h

@property (nonatomic, copy) NSString *属性名称1;
@property (nonatomic, copy) NSString *属性名称2;

//.m 必须通过setter方法改变值或者KVC

KVO方式

1 //触发的事件
2 [indexCollectionView addObserver:self forKeyPath:@"属性名称" options:NSKeyValueObservingOptionNew context:nil];
3         [posterCollectionView addObserver:self forKeyPath:@"pathIndex" options:NSKeyValueObservingOptionNew context:nil];
4 - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
5     //得到改变后的新值
6     NSInteger index = [[change objectForKey:@"new"] integerValue];
7
8     }
9 }

Block block的返回值 block的名称 block的参数

1 typedef void(^SucccessBlock)(NSString *); //Block的定义
2 @property(nonatomic,copy)SucccessBlock loginBlock;  //block的声明  要用copy防止block的循环引用
3 _freindBlcok(friends); block的调用
4 [[MyXMPPManager shareManager] getFreind:^(NSArray *freinds) {}   //block的赋值 实现