iOS 利用UserDefaults快速实现常用搜索页记录工具

1.需求分析

一般搜索页的历史记录需求

1. 存储内容为字符串
2. 存储内容要去重
3. 存储个数会有个上限
4. 存储个数达到上限后要先前挤掉旧数据,保留新数据
5. 调用动作一般为 存 / 读 / 清空一律

2.实现

.h文件

//  RPCustomTool.h//  RollingPin////  Created by RollingPin on 2020/12/31.//  Copyright © 2020 RollingPin. All rights reserved.//#import <Foundation/Foundation.h>#import <UIKit/UIKit.h>@interface RPCustomTool : NSObject/// 存+ (void)saveHistoryString:(NSString *)saveStr;/// 读+ (NSArray *)readHistoryList;/// 清空+ (void)deleteHistoryList;@end

.m文件

//  RPCustomTool.h//  RollingPin////  Created by RollingPin on 2020/12/31.//  Copyright © 2020 RollingPin. All rights reserved.//#import "RPCustomTool.h"@implementation RPCustomTool#pragma mark - 存+ (void)saveHistoryString:(NSString *)saveStr{    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];    NSArray *savedArray = [userDefaults arrayForKey:@"RPSearchHistoryMark"];    NSMutableArray *savedMuArray = [[NSMutableArray alloc]initWithArray:savedArray];    //去重    NSString *repetitiveStr = @"";    for (NSString * oneStr in savedArray) {        if ([oneStr isEqualToString:saveStr]) {            repetitiveStr = oneStr;            break;        }    }    if (repetitiveStr.length >0) {        [savedMuArray removeObject:repetitiveStr];    }    [savedMuArray addObject:saveStr];    //设置最大保存数    if(savedMuArray.count > 10)    {        [savedMuArray removeObjectAtIndex:0];    }    //最后再存储到NSUserDefaults中    [userDefaults setObject:savedMuArray forKey:@"RPSearchHistoryMark"];    [userDefaults synchronize];}#pragma mark - 读+ (NSArray *)readHistoryList{    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];    //读取数组NSArray类型的数据    NSArray *savedArray = [userDefaults arrayForKey:@"RPSearchHistoryMark"];    NSLog(@"savedArray======%@",savedArray);    return [savedArray copy];}#pragma mark - 清空+ (void)deleteHistoryList{    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];    [userDefaults setObject:[NSArray array] forKey:@"RPSearchHistoryMark"];    [userDefaults synchronize];}@end