登录界面多个账户信息存储问题

                  

方法一：使用归档：其实质就是读写文件操作，（归档，解档：archive，unarchive）

// 归档+ (NSData *)archivedDataWithRootObject:(id)rootObject;+ (BOOL)archiveRootObject:(id)rootObject toFile:(NSString *)path;

// 解档+ (id)unarchiveObjectWithData:(NSData *)data;+ (id)unarchiveObjectWithFile:(NSString *)path;

归档写入文件有两种：

1.一个文件只保存一个对象

此种情况就是上面的简单归档，解档，如上两段代码。

2.一个文件保存多个对象

此种情况就是相当于写文件操作，

具体看以下代码：

-(void)saveDoctorInfo:(DoctorModel *)doctor；

-(DoctorModel *)getDoctorInfo:(NSString *)accid；

注：

NSKeyedArchiver *archiver = [[NSKeyedArchiveralloc]initForWritingWithMutableData:data];  

/ /创建NSKeyedArchiver实例，用于将对象归档到此theData实例中。

 一个文件保存多个用户带来的问题有：

（1.）可以按顺序存储用户数据，但是不好限制保存个数（假如限制保存三个用户信息）

对于文件中的内容操作，只有读写，但是如果保存的用户越来越多，文件会越来越大。

如果要删除文件中的数据（字符串）只能用指针来实现。

第一种是用空字符串覆盖掉你所需要修改的数据。第二种是找到初始指针，往后一直写，数据便会覆盖掉。但是所要删除的对象数据结束指针位置难以知道。如果要删除的对象是第二个，则很有可能会把第三个用户信息覆盖掉。

（2.）无法按顺序取出保存的用户：

因为存储，查询文件中的对象使用的方法为：

- (void)encodeObject:(id)objv forKey:(NSString *)key;

- (id)decodeObjectForKey:(NSString *)key;

相当于文件中存储对象的方式是字典类型的，无法像数组那样获得顺序

////  DoctorManager.m//  com.yx129.yxClientDoctor3////  Created by yx on 15/2/11.//  Copyright (c) 2015年 Guangzhou Yixiang Internet Technology Development Limited. All rights reserved.//#define fileName_LastDoctorInfo @"lastDoctor.info"#define fileName_SavedDoctorInfo @"savedDoctor.info"//#define klastDoctorEncodeKey  @"lastDoctor"#define ksavedDoctorEncodeKey  @"savedDoctor"#import "DoctorManager.h"@implementation DoctorManager{//    NSMutableDictionary * _lastDoctorInfoDic;//    NSString *_lastDoctorInfoPath;}static DoctorManager * manager=nil;static DoctorModel *lastDoctor = nil;static DoctorModel *toolDoctor = nil;static DoctorModel *savedDoctor = nil;+(id)shareDoctorManager{    static dispatch_once_t onceToken;    dispatch_once(&onceToken, ^{        manager=[[DoctorManager alloc]init];        toolDoctor = [[DoctorModel alloc] init];    });        return manager;}+(DoctorModel *)getSavedDoctor{     if (savedDoctor == nil){        savedDoctor = [[DoctorModel alloc] init];    }    return savedDoctor;}-(id)init{    if (self=[super init]) {        //   _lastDoctorInfoPath=[NSString stringWithFormat:@"%@/Documents/lastDoctorInfo.plist",NSHomeDirectory()];            }    return self;    }-(void)saveLastLoginDoctor:(DoctorModel *)doctor{    //    NSString *docPath=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject];//    NSString *path=[docPath stringByAppendingPathComponent:fileName_LastDoctorInfo];        NSString *path =[self getFilePath:fileName_LastDoctorInfo];        [NSKeyedArchiver archiveRootObject:doctor toFile:fileName_LastDoctorInfo];}-(DoctorModel *)getLastLoginDoctor{    if (!lastDoctor) {        lastDoctor=[[DoctorModel alloc]init];            }    //    NSString *docPath=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];//    NSString *path=[docPath stringByAppendingPathComponent:fileName_LastDoctorInfo];        NSString *path =[self getFilePath:fileName_LastDoctorInfo];    lastDoctor = [NSKeyedUnarchiver unarchiveObjectWithFile:path];        return lastDoctor;}#pragma 保存账户信息-(void)saveDoctorInfo:(DoctorModel *)doctor{    NSMutableData *data = [[NSMutableData alloc] init];    NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];    [archiver encodeObject:doctor forKey:doctor.acc_id];    [archiver finishEncoding];    [data writeToFile:[self getFilePath:fileName_SavedDoctorInfo] atomically:YES];}-(DoctorModel *)getDoctorInfo:(NSString *)accid{    if ([[NSFileManager defaultManager] fileExistsAtPath:[self getFilePath:fileName_SavedDoctorInfo]]) {        NSData *data = [[NSData alloc] initWithContentsOfFile:[self getFilePath:fileName_SavedDoctorInfo]];        NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];                 if (!lastDoctor) {            lastDoctor=[[DoctorModel alloc]init];        }        lastDoctor = [unarchiver decodeObjectForKey:accid];        [unarchiver finishDecoding];            }        return lastDoctor;}-(DoctorModel *)getLastSavedDoctorInfo{        DoctorModel *lastSavedDoctor=[[DoctorModel alloc]init];        lastSavedDoctor = [NSKeyedUnarchiver unarchiveObjectWithFile:[self getFilePath:fileName_LastDoctorInfo]];        return lastSavedDoctor;}-(NSString *)getFilePath:(NSString *)fileName{        NSArray *array =  NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);        return [[array objectAtIndex:0] stringByAppendingPathComponent:fileName];}/*-(void)saveLastLoginDoctor:(DoctorModel *)doctor{    NSString *docPath=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject];    NSString *path=[docPath stringByAppendingPathComponent:@"lastDoctor.info"];    NSLog(@"path=%@",path);    toolDoctor = doctor;    [NSKeyedArchiver archiveRootObject:toolDoctor toFile:path];}-(DoctorModel *)getLastLoginDoctor{        if (!lastDoctor) {        lastDoctor=[[DoctorModel alloc]init]; //  设置状态，是否已经进入信息详情页面                NSString *docPath=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject];        NSString *path=[docPath stringByAppendingPathComponent:@"person.yangyang"];        NSLog(@"path=%@",path);                toolDoctor = [NSKeyedUnarchiver unarchiveObjectWithFile:path];    }        lastDoctor = toolDoctor;    //    if (!lastDoctor) {//        lastDoctor=[[DoctorModel alloc]init]; //  设置状态，是否已经进入信息详情页面//        //        NSString *docPath=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject];//        NSString *path=[docPath stringByAppendingPathComponent:@"person.yangyang"];//        NSLog(@"path=%@",path);//        //        lastDoctor = [NSKeyedUnarchiver unarchiveObjectWithFile:path];//    }        return lastDoctor;}//-(void)synchronize//{//    [_lastDoctorInfoDic writeToFile:_lastDoctorInfoPath atomically:YES];//    //    [_lastDoctorInfoDic removeAllObjects];//    //}  */@end

由于以上原因，当你需要增删查改多个对象时，不能采用直接保存多个对象形式，而要将对象用数组包装，再将这个数组写入归档。

这时候根对象是数组。

+ (BOOL)archiveRootObject:(id)rootObject toFile:(NSString *)path;

-(void)saveDoctor:(DoctorModel *)doctor{    NSString *path =[self getFilePath:fileName_SavedDoctorInfo];    NSMutableArray *doctorsArr = [NSKeyedUnarchiver unarchiveObjectWithFile:path];        if (doctorsArr == nil) {        doctorsArr = [NSMutableArray arrayWithObject:doctor];    }else{                if (doctorsArr.count >= 5)            [doctorsArr removeObjectAtIndex:0];                        [doctorsArr addObject:doctor];    }        [NSKeyedArchiver archiveRootObject:doctorsArr toFile:fileName_SavedDoctorInfo];}-(DoctorModel *)getDoctor:(NSString *)accid{        NSString *path =[self getFilePath:fileName_SavedDoctorInfo];    NSMutableArray *doctorsArr = [NSKeyedUnarchiver unarchiveObjectWithFile:path];        DoctorModel *aDoctor;        if (doctorsArr != nil) {                for (DoctorModel *savedDoc in doctorsArr) {                        if ([savedDoc.acc_id isEqualToString:accid]) {                                aDoctor = savedDoc;                break;            }        }            }        return aDoctor;}-(NSString *)getFilePath:(NSString *)fileName{        NSArray *array =  NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);        return [[array objectAtIndex:0] stringByAppendingPathComponent:fileName];}

方法二：用plist 

需要用将数据加密后再进行存储

md5 只能 加密不能解密

应用 aes 加密算法

此种方法，排序是个问题