变更记录

序号 录入时间 录入人 备注
1 2015-06-09 Alfred Jiang -
2 2015-12-23 Alfred Jiang -

方案名称

NSMutableSet - 在 NSMutableSet 中添加自定义对象时怎么保证不重复

关键字

NSMutableSet \ hash \ isEqual \ 重复

需求场景

  1. 需要将自定义对象添加入 NSMutableSet，需要保证不重复
  2. 避免存储自定义重复对象

参考链接

  1. NSHipster - Equality

详细内容

通过自定义 hasn 与 isEqual 方法定义相等条件

示例代码如下：

ALFImport.h

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//
//  ALFImport.h
//  ALFUMLTool
//
//  Created by Alfred Jiang on 6/8/15.
//  Copyright (c) 2015 Alfred Jiang. All rights reserved.
//

#import <Foundation/Foundation.h>

typedef NS_ENUM(NSInteger, ImportType) {
    IMPORT_TYPE_SYSTEM = 0,
    IMPORT_TYPE_USER,
    IMPORT_TYPE_WEAK
};

@interface ALFImport : NSObject
{
    ImportType type;
    NSString *name;
//    NSArray *classes;
}

@property(nonatomic,assign) ImportType type;
@property(nonatomic,strong) NSString *name;
//@property(nonatomic,strong) NSArray *classes;

- (NSUInteger)hash;
- (BOOL)isEqual:(id)object;
- (NSString *)description;

@end

ALFImport.m

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//
//  ALFImport.m
//  ALFUMLTool
//
//  Created by Alfred Jiang on 6/8/15.
//  Copyright (c) 2015 Alfred Jiang. All rights reserved.
//

#import "ALFImport.h"

@implementation ALFImport
@synthesize type;
@synthesize name;
//@synthesize classes;

- (BOOL)isEqualToImport:(ALFImport *)import {
    if (!import) {
        return NO;
    }

    BOOL haveEqualType = (!self.type && !import.type) || (type == import.type);
    BOOL haveEqualName = (!self.name && !import.name) || [self.name isEqualToString:import.name];

    return haveEqualType && haveEqualName;
}

- (NSUInteger)hash
{
     return self.type ^ [self.name hash];
}

- (BOOL)isEqual:(id)object
{
    if (self == object) {
        return YES;
    }

    if (![object isKindOfClass:[ALFImport class]]) {
        return NO;
    }

    return [self isEqualToImport:(ALFImport *)object];
}

- (NSString *)description
{
    return [NSString stringWithFormat:@"Import Name : %@",name];
}

@end

效果图

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备注

（无）