GCDMulticastDelegate使用

Talk is cheap, show me the code.

• 在工具类中处理业务逻辑

#import <Foundation/Foundation.h>
#import "GCDMulticastDelegate.h"
@protocol ManagerDelegate<NSObject>
- (void)doSomething;
@end

@interface Manager : NSObject
{
    GCDMulticastDelegate<ManagerDelegate> *_delegates;
}
+ (instancetype)sharedManager;

- (void)letusDoSomething;

- (void)_addDelegate:(id<ManagerDelegate>)delegate delegateQueue:(dispatch_queue_t)queue;
- (void)removeDelegate:(id<ManagerDelegate>)delegate;
@end

#import "Manager.h"

static Manager *manager = nil;
static NSObject *g_lock = nil;
@implementation Manager

+ (instancetype)sharedManager
{
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        manager = [[Manager alloc] init];
    });
    return manager;
}

- (instancetype)init
{
    self = [super init];
    if (self) {
        _delegates = (GCDMulticastDelegate<ManagerDelegate> *)[[GCDMulticastDelegate alloc] init];
        g_lock = [[NSObject alloc] init];
    }
    return self;
}

- (void)_addDelegate:(id<ManagerDelegate>)delegate delegateQueue:(dispatch_queue_t)queue
{
    @synchronized(g_lock) {
        if (!queue) {
            queue = dispatch_get_main_queue();
        }
        [_delegates addDelegate:delegate delegateQueue:queue];
    }
}
- (void)removeDelegate:(id<ManagerDelegate>)delegate
{
    if (!delegate) {
        return;
    }
    @synchronized(g_lock) {
        [_delegates removeDelegate:delegate];
    }
}

- (void)letusDoSomething
{
    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(5 * NSEC_PER_SEC)), queue, ^{
        [_delegates doSomething];
    });
}
@end

• 在Appdelegate和ViewController中都遵守<ManagerDelegate>并实现协议中声明的方法

@interface AppDelegate ()<ManagerDelegate>
@end
@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    [[Manager sharedManager] _addDelegate:self delegateQueue:nil];
    return YES;
}
- (void)doSomething
{
    NSThread *thread = [NSThread currentThread];
    NSLog(@"Appdelegate:%@",thread);
}

- (void)viewDidLoad {
    [super viewDidLoad];
    dispatch_queue_t qt = dispatch_queue_create("testmd.f.f", DISPATCH_QUEUE_SERIAL);
    [[Manager sharedManager] _addDelegate:self delegateQueue:qt];
}

- (void)doSomething {
    NSThread *thread = [NSThread currentThread];
    NSLog(@"VC:%@",thread);
}

- (void)dealloc {
    NSLog(@"dealloc");
}

• 在VC的touchBegin方法中调用letusDoSomething方法

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    [[Manager sharedManager] letusDoSomething];
}

5s后打印信息如下：

2018-04-27 16:22:30.708421+0800 GCDMulticastDelegateDemo[1627:206523] Appdelegate:<NSThread: 0x60400006b580>{number = 1, name = main}
2018-04-27 16:22:30.708423+0800 GCDMulticastDelegateDemo[1627:206644] VC:<NSThread: 0x600000262080>{number = 3, name = (null)}

• 在业务逻辑执行期间把delegate移除掉

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    [[Manager sharedManager] letusDoSomething];
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(3 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        
        [[Manager sharedManager] removeDelegate:self];
    });
}

打印信息如下：

2018-04-27 16:27:06.424868+0800 GCDMulticastDelegateDemo[1652:217365] Appdelegate:<NSThread: 0x604000076000>{number = 1, name = main}

• github地址

  GCDMulticastDelegate