三方库KVOController的使用及源码分析

KVOController的github地址

pod 'KVOController'

@interface TestModel : NSObject
@property (nonatomic,strong)NSString  *name;
@property (nonatomic,assign)int  age;
@end

@implementation TestModel
@end

------------------------------------------------

#import "KVOBaseUsesViewController_14.h"
#import "KVOBaseUsesViewController_14_2.h"
#import <KVOController/KVOController.h>

@interface KVOBaseUsesViewController_14 ()
@property (nonatomic,strong)TestModel  *t;
@property (nonatomic,strong)FBKVOController *fbKVOController;
@end

@implementation KVOBaseUsesViewController_14
- (void)viewDidLoad {
   [super viewDidLoad];
  
   //初始化：方式1 (类方法) 
   self.fbKVOController = [FBKVOController controllerWithObserver:self];
  
   //初始化：方式2 （实例方法）
   self.fbKVOController = [[FBKVOController   alloc]initWithObserver:self];
   
   //初始化：方式3 （实例方法） 持有 默认YES
   self.fbKVOController = [[FBKVOController   alloc]initWithObserver:self retainObserved:YES];
    
   //初始化：方式4 （实例方法） 不持有
   self.fbKVOController = [[FBKVOController   alloc]initWithObserver:self retainObserved:NO];
   
   -------------------------------------------------------------
   
   //监听：方式1 通过SEL来监听
   [self.fbKVOController observe:self.t keyPath:@"name" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld action:@selector(propertyHasChanged:)];
   
   //监听：方式2 通过block来监听
   [self.fbKVOController observe:self.t keyPath:@"age" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld block:^(id  _Nullable observer, id  _Nonnull object, NSDictionary<NSString *,id> * _Nonnull change) {
          NSLog(@"监听者%@监听到%@的属性值改变了 - %@",observer, object, change);
     }];
    
    
   //监听：方式3 带上下文 实现：observeValueForKeyPath方法来监听
   [self.fbKVOController observe:self.t keyPath:@"age" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:@"theWay3"];
    
    //监听：方式4  可以监听多个属性 通过SEL来监听
    [self.fbKVOController observe:self.t keyPaths:@[@"name",@"age"] options:NSKeyValueObservingOptionNew |NSKeyValueObservingOptionOld action:@selector(propertyHasChanged:)];

    
    //监听：方式5  可以监听多个属性 通过block监听
    [self.fbKVOController observe:self.t keyPaths:@[@"name",@"age"] options:NSKeyValueObservingOptionNew |NSKeyValueObservingOptionOld block:^(id  _Nullable observer, id  _Nonnull object, NSDictionary<NSString *,id> * _Nonnull change) {
        NSLog(@"监听者%@监听到%@的属性值改变了 - %@",observer, object, change);
   }];
    
    //监听：方式6  可以监听多个属性 带上下文 实现：observeValueForKeyPath方法来监听
   [self.fbKVOController observe:self.t keyPaths:@[@"name",@"age"] options:NSKeyValueObservingOptionNew |NSKeyValueObservingOptionOld context:@"theWay6"];
}


//通过上下文的方法来监听的（实现监听方法）
-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context{
     NSLog(@"监听到%@的%@属性值改变了 - %@ - %@", object, keyPath, change, context);
}

//通过SEL的方法来监听的（实现监听方法）
-(void)propertyHasChanged:(id)sender{
    NSLog(@"属性改变啦：%@",sender);
}


//点击修改属性
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    self.t.name = @"Lucy";
    self.t.age = 18;
}

-(void)dealloc{
    //注销方式1
    [self.fbKVOController unobserve:self.t keyPath:@"name"];   
    //[self.fbKVOController unobserve:self.t keyPath:@"name"];  过多的移除不会崩溃哟 
     
    //注销方式2
    [self.fbKVOController unobserve:self.t];
   // [self.fbKVOController unobserve:self.t]; 过多的移除不会崩溃哟 
    
    //注销方式3
    [self.fbKVOController unobserveAll];
    
    NSLog(@"%s",__FUNCTION__);
}

我们再细看初始化：方式3 和方式4（是否持有）

- (void)viewDidLoad {
    [super viewDidLoad];
    
    UIButton *jumpBtn = [UIButton new];
    jumpBtn.frame = CGRectMake(20, 100, 150, 80);
    [self.view  addSubview:jumpBtn];
    [jumpBtn setTitle:@"跳转VC" forState:UIControlStateNormal];
    [jumpBtn setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
    [jumpBtn addTarget:self action:@selector(jump) forControlEvents:UIControlEventTouchUpInside];
    
     self.t  = [[TestModel alloc]init];
     
     
    //设置监听者为 self
    //持有
    self.fbKVOController = [[FBKVOController   alloc]initWithObserver:self retainObserved:YES];
    
    //不持有
    self.fbKVOController = [[FBKVOController   alloc]initWithObserver:self retainObserved:NO];

}

-(void)propertyHasChanged:(id)sender{
    NSLog(@"属性改变啦：%@",sender);
}

-(void)jump{
    KVOBaseUsesViewController_14_2* vc2 = [KVOBaseUsesViewController_14_2 new];
    vc2.vc1 = self;
    
    //设置监听的对象是vc2,监听的属性是vc1.t.name
    [self.fbKVOController observe:vc2 keyPath:@"vc1.t.name" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld action:@selector(propertyHasChanged:)];
    [self.navigationController pushViewController:vc2 animated:YES];
    
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(3.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        self.t.name = @"Jack";
        self.t.age = 16;
    });
}
-(void)dealloc{    
    //注销
    [self.fbKVOController unobserveAll];
    NSLog(@"%s",__FUNCTION__);
}


KVOBaseUsesViewController_14_2.h

#import <UIKit/UIKit.h>
#import "KVOBaseUsesViewController_14.h"

@interface KVOBaseUsesViewController_14_2 : UIViewController
@property (nonatomic,strong)KVOBaseUsesViewController_14  *vc1;
@end

KVOBaseUsesViewController_14_2.m
#import "KVOBaseUsesViewController_14_2.h"

@interface KVOBaseUsesViewController_14_2 ()
@end

@implementation KVOBaseUsesViewController_14_2
- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
}

-(void)dealloc{
    NSLog(@"%s",__FUNCTION__);
}
@end

分析：
1.当设置retained的为YES,持有，则2个控制器都不会被释放（没有走dealloc的方法）
2.当设置retained的为NO,不持有，则2个控制器会被释放（走dealloc的方法）

首先我们看下该框架的文件

KVOController.h
FBKVOController.h
FBKVOController.m
NSObject+FBKVOController.h
NSObject+FBKVOController.m

image

我们从上面的类分析有如下图关系：

image

具体的代码实现及说明：可参考写的gitHubDemo里面主要的步骤都加了注释

友情链接：