day07-04-单例

Objective-c

//  main.m
//  day07-04-单例
//
//  Created by Aaron on 15/7/9.
//  Copyright (c) 2015年 Aaron. All rights reserved.
//
#import <Foundation/Foundation.h>
//单例
//设计模式
//一个类只会产生一个实例,而且不释放
//这个实例叫做单例对象
//这个类叫做单例类
//单例的应用场景
//废纸篓
//网页计数器
//单例的作用: 共享数据,用作管理
#import "TaskManager.h"
#import "TaskOne.h"
#import "TaskTwo.h"
void test()
{
    TaskManager *manager = [TaskManager defaultManager];
    NSLog(@"%p",manager);
//day07-04-单例[2128:174387] 0x10030fea0
}
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        TaskManager *manager = [TaskManager defaultManager];
        NSLog(@"%p",manager);
//day07-04-单例[2128:174387] 0x10030fea0
        TaskOne *one = [[TaskOne alloc] init];
        [one TaskRun];
        TaskTwo *two = [[TaskTwo alloc] init];
        [two TaskRun];
        TaskTwo *two1 = [[TaskTwo alloc] init];
        [two1 TaskRun];
        //manager = nil;
        [manager zhuxiao];
        NSLog(@"%@",manager.taskArray);
        //test();
    }
    return 0;
}

#import "Task.h"
@interface TaskOne : Task
@end

#import "TaskOne.h"
@implementation TaskOne
-(instancetype)init
{
    if(self = [super init])
    {
        self.name = @"taskOne";
    }
    return self;
}
@end

#import "Task.h"
@interface TaskTwo : Task
//-(void)TaskRun;
@end

#import "TaskTwo.h"
#import "TaskManager.h"
@implementation TaskTwo
-(instancetype)init
{
    if(self = [super init])
    {
        self.name = @"taskTwo";
    }
    return self;
}
-(void)TaskRun
{
    TaskManager *manager = [TaskManager defaultManager];
    NSLog(@"TaskTwo.h  %p",manager);
    //NSLog(@"%ld",manager.number);
}
@end

#import <Foundation/Foundation.h>
#import "Task.h"
@interface TaskManager : NSObject
@property (nonatomic,assign) NSInteger number;
@property (nonatomic,retain) NSMutableArray *taskArray;
//单例方法通常以default 或者share 开头
//单例类需要用单例方法来创建对象
+(instancetype)defaultManager;
-(void)addTask:(Task *)task;
-(void)zhuXiao;
@end

#import "TaskManager.h"
@implementation TaskManager
static TaskManager *manager = nil;
+(instancetype)defaultManager
{
//    static TaskManager *manager = nil;
    //加锁
    @synchronized(self)
    {
        if(!manager)
        {
            manager = [[self alloc] init];
        }
    }
    return manager;
}
-(void)zhuXiao
{
    manager = nil;
}
-(void)addTask:(Task *)task
{
    if(!_taskArray)
    {
        _taskArray = [NSMutableArray array];
    }
    [_taskArray addObject:task];
}
@end

#import <Foundation/Foundation.h>
@interface Task : NSObject
@property (nonatomic,copy) NSString *name;
-(void)TaskRun;
@end

#import "Task.h"
#import "TaskManager.h"
@implementation Task
-(void)TaskRun
{
    TaskManager *manager = [TaskManager defaultManager];
    NSLog(@"TaskOne.h  %p",manager);
    manager.number = 1000;
    [manager addTask:self];
}
@end