iOS 一对多代理

时间:2022-05-23 执笔续春秋人气:0

实现方案一

利用可变数组。签协议方需要add到代理的数组中，然后协议遍历数组中的对象，进行分发。
缺点是需要数组对其内部元素是强引用，需要在合适的地方对其进行释放，否则会有内存泄漏

代理协议的对象.h写法

#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@protocol TestSubViewDelegate <NSObject>

- (void)testSendSomeMessageToOther:(NSString *)somethings;

- (void)testSendSome:(NSString *)somethings;

@end


@interface TestSubView : UIView

//@property (nonatomic, weak)id <TestSubViewDelegate>delegate;

@property (nonatomic, strong)NSMutableArray <id<TestSubViewDelegate>>* __nullable delegates;

- (void)addDelegate:(id<TestSubViewDelegate>)delegate;

// 需要在合适的地方销毁对象。
- (void)destory;
@end

NS_ASSUME_NONNULL_END

.m代理协议分发机制

#import "TestSubView.h"

@interface TestSubView ()

@end

@implementation TestSubView

- (instancetype)init {
    if (self = [super init]) {
        self.delegates = [NSMutableArray array];
        
        // 测试，执行
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
            [self test1DelegateAction];
        });
        
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
            [self test2DelegateAction];
        });
        
    }
    return self;
}

// 测试代理方法分发1
- (void)test1DelegateAction {
    [self.delegates enumerateObjectsUsingBlock:^(id<TestSubViewDelegate>  _Nonnull delegate, NSUInteger idx, BOOL * _Nonnull stop) {
        if ([delegate respondsToSelector:@selector(testSendSomeMessageToOther:)]) {
            [delegate testSendSomeMessageToOther:@"传递的Some"];
        }
    }];
}

// 测试代理分发2
- (void)test2DelegateAction {
    [self.delegates enumerateObjectsUsingBlock:^(id<TestSubViewDelegate>  _Nonnull delegate, NSUInteger idx, BOOL * _Nonnull stop) {
        if ([delegate respondsToSelector:@selector(testSendSome:)]) {
            [delegate testSendSome:@"传递的Some2-"];
        }
    }];
}


- (void)destory {
    [self.delegates removeAllObjects];
    self.delegates = nil;
}

- (void)addDelegate:(id<TestSubViewDelegate>)delegate {
    [self.delegates addObject:delegate];
}

签订代理方1

#import "View1Controller.h"
#import "TestSubView.h"

@interface View1Controller ()<TestSubViewDelegate>

@end

@implementation View1Controller

- (void)viewDidLoad {
    [super viewDidLoad];
    TestSubView *ts = [TestSubView new];
    [ts addDelegate:self];
    [self.view addSubview:ts];
}

#pragma mark - TestSubViewDelegate
- (void)testSendSomeMessageToOther:(NSString *)somethings {
    NSLog(@"%@", somethings);
}

- (void)testSendSome:(NSString *)somethings {
    NSLog(@"%@", somethings);
}
 
@end

签订方2

#import "ViewController.h"
#import "View1Controller.h"
#import "TestSubView.h"

@interface ViewController ()<TestSubViewDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    TestSubView *ts = [TestSubView new];
    [ts addDelegate:self];
    [self.view addSubview:ts];
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    View1Controller *vc = [View1Controller new];
    [self presentViewController:vc animated:YES completion:nil];
}

#pragma mark - TestSubViewDelegate
- (void)testSendSomeMessageToOther:(NSString *)somethings {
    NSLog(@"%@", somethings);
}

@end

实现方案二

采用NSPointerArray去声明delegates的数组，这样就可以不用操心管理内存泄漏的问题，因为NSPointerArray里面的元素都是weak化的。会随着当前对象释放而释放掉。

还有一些NSHashTable NSMapTable 等等，实现方式大同小异。

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