Objective C 中的多个委托

在Objective C中，委托是一种常用的设计模式，用于实现对象之间的通信和交互。通过委托，一个对象可以将特定的任务委托给另一个对象来完成，从而实现代码的模块化和解耦。

objective-c
// 定义委托协议
@protocol MyDelegate 
- (void)doTask;
@end
// 委托对象A
@interface DelegateA : NSObject 
@end
@implementation DelegateA
- (void)doTask {
    NSLog(@"Delegate A is doing the task.");
}
@end
// 委托对象B
@interface DelegateB : NSObject 
@end
@implementation DelegateB
- (void)doTask {
    NSLog(@"Delegate B is doing the task.");
}
@end
// 需要进行委托的对象
@interface MyObject : NSObject
@property (nonatomic, weak) id delegateA;
@property (nonatomic, weak) id delegateB;
- (void)triggerTask;
@end
@implementation MyObject
- (void)triggerTask {
    [self.delegateA doTask];
    [self.delegateB doTask];
}
@end
// 使用多个委托的示例
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        MyObject *obj = [[MyObject alloc] init];
        
        DelegateA *delegateA = [[DelegateA alloc] init];
        DelegateB *delegateB = [[DelegateB alloc] init];
        
        obj.delegateA = delegateA;
        obj.delegateB = delegateB;
        
        [obj triggerTask];
    }
    return 0;
}

Delegate A is doing the task.
Delegate B is doing the task.