IOS开发-数据持久化（一）【文本文件+二进制归档】

概要

    数据持久化分为不同的方式，本章主要简示了数据归档（一般而说的序列化）和写XML的文本文件方式。其中XML文本方式主要使用NSArray或者NSDictionary的writeToFile方法，而数据归档使用了NSKeyedArchiver/NSKeyedUnarchiver等实现数据的归档（序列化）。

结果展示

程序展示

数据化文件

      注意新版本的IOS模拟器的目录和以前的目录不在同一个地方，其中plist文件是XML文件，可打开直接查看，而archi是归档的二进制文件。

流程概要

1.新建工程，拖拉界面，完成程序除归档外的操作，具体操作：略

2.对于XML存储，将需要存储的数据放到字典或者数组中，然后调用WriteToFile把数据保存到文件，使用类方法initWithContentsOfFile读取存储的数据即可

3.数据归档化相对而言较复杂点，需要新建一个数据类，该类需要实现了NSCoding协议，然后实现编码和解码两个方法。

4.在需要数据存储的地方把需要的数据放到步骤3中的数据类的对象中，然后结合使用NSMutableData和NSKeyedArchiver实现数据归档。

5.略

主要代码

数据类

h文件

////  Staff.h//  DataXMLArchiver////  Created by God Lin on 14/12/9.//  Copyright (c) 2014年 arbboter. All rights reserved.//#import <Foundation/Foundation.h>@interface Staff : NSObject <NSCoding>{    NSString* _nickName;    NSString* _email;    NSString* _phone;    NSString* _sex;    NSString* _position;}@property (nonatomic, retain) NSString* _nickName;@property (nonatomic, retain) NSString* _email;@property (nonatomic, retain) NSString* _phone;@property (nonatomic, retain) NSString* _sex;@property (nonatomic, retain) NSString* _position;@end

m文件

////  Staff.m//  DataXMLArchiver////  Created by God Lin on 14/12/9.//  Copyright (c) 2014年 arbboter. All rights reserved.//#import "Staff.h"@implementation Staff@synthesize _nickName;@synthesize _email;@synthesize _phone;@synthesize _sex;@synthesize _position;#pragma NSCoding 实现序列化（归档）- (void)encodeWithCoder:(NSCoder *)aCoder{    [aCoder encodeObject:self._nickName forKey:@"nickName"];    [aCoder encodeObject:self._email forKey:@"email"];    [aCoder encodeObject:self._phone forKey:@"phone"];    [aCoder encodeObject:self._sex forKey:@"sex"];    [aCoder encodeObject:self._position forKey:@"position"];}- (id)initWithCoder:(NSCoder *)aDecoder{    self._nickName = [aDecoder decodeObjectForKey:@"nickName"];    self._email = [aDecoder decodeObjectForKey:@"email"];    self._phone = [aDecoder decodeObjectForKey:@"phone"];    self._sex = [aDecoder decodeObjectForKey:@"sex"];    self._position = [aDecoder decodeObjectForKey:@"position"];    return self;}@end

程序主体代码

h文件

////  ViewController.h//  DataXMLArchiver////  Created by God Lin on 14/12/9.//  Copyright (c) 2014年 arbboter. All rights reserved.//#import <UIKit/UIKit.h>@interface ViewController : UIViewController{    IBOutlet UITextField* _textNickName;    IBOutlet UITextField* _textEmail;    IBOutlet UITextField* _textPhone;    IBOutlet UITextField* _textSex;    IBOutlet UITextField* _textPosition;}@property (nonatomic, retain) UITextField* _textNickName;@property (nonatomic, retain)UITextField* _textEmail;@property (nonatomic, retain)UITextField* _textPhone;@property (nonatomic, retain)UITextField* _textSex;@property (nonatomic, retain)UITextField* _textPosition;-(IBAction)onHideKeyboard:(id)sender;-(IBAction)onXmlSave:(id)sender;-(IBAction)onXmlLoad:(id)sender;-(IBAction)onArchiverSave:(id)sender;-(IBAction)onArchiverLoad:(id)sender;@end

m文件

////  ViewController.m//  DataXMLArchiver////  Created by God Lin on 14/12/9.//  Copyright (c) 2014年 arbboter. All rights reserved.//#import "ViewController.h"#import "Staff.h"@interface ViewController ()@end@implementation ViewController@synthesize _textNickName;@synthesize _textEmail;@synthesize _textPhone;@synthesize _textSex;@synthesize _textPosition;-(IBAction)onHideKeyboard:(id)sender{    [sender resignFirstResponder];}-(NSString*)getDocumentDir{    // 获取保存的文件名    NSArray* arrayPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    return [arrayPath objectAtIndex:0];}-(void)textClear{    self._textNickName.text = @"";    self._textEmail.text = @"";    self._textPhone.text = @"";    self._textSex.text = @"";    self._textPosition.text = @"";}// XML文本保存数据，可使用数组字典等保存数据-(IBAction)onXmlSave:(id)sender{    // 保存数据到字典    NSMutableDictionary* dict = [[NSMutableDictionary alloc] init];    [dict setObject:self._textNickName.text forKey:@"nickName"];    [dict setObject:self._textEmail.text forKey:@"email"];    [dict setObject:self._textPhone.text forKey:@"phone"];    [dict setObject:self._textSex.text forKey:@"sex"];    [dict setObject:self._textPosition.text forKey:@"position"];        NSString* pathFile = [self getDocumentDir];    pathFile = [pathFile stringByAppendingPathComponent:@"staff.plist"];        // 数据写入文件    [dict writeToFile:pathFile atomically:YES];        UIAlertView* alert = [[UIAlertView alloc] initWithTitle:@"Infomation" message:@"Save finished" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];    [alert show];    // 使用ARC，自己不需要管理内存    //[alert release];    [self textClear];}-(IBAction)onXmlLoad:(id)sender{    // 获取保存的文件名    NSString* pathFile = [self getDocumentDir];    pathFile = [pathFile stringByAppendingPathComponent:@"staff.plist"];        NSDictionary* dict = [[NSDictionary alloc] initWithContentsOfFile:pathFile];    self._textNickName.text = [dict objectForKey:@"nickName"];    self._textEmail.text = [dict objectForKey:@"email"];    self._textPhone.text = [dict objectForKey:@"phone"];    self._textSex.text = [dict objectForKey:@"sex"];    self._textPosition.text = [dict objectForKey:@"position"];        UIAlertView* alert = [[UIAlertView alloc] initWithTitle:@"Infomation" message:@"Load finished" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];    [alert show];}// 归档化数据-(IBAction)onArchiverSave:(id)sender{    Staff* staff = [[Staff alloc] init];    staff._nickName = self._textNickName.text;    staff._email = self._textEmail.text;    staff._phone = self._textPhone.text;    staff._sex = self._textSex.text;    staff._position = self._textPosition.text;        // 新建二进制内存(读写)    NSMutableData* data = [[NSMutableData alloc] init];        // 设置二进制内存数据内容（读写）    NSKeyedArchiver* archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];    [archiver encodeObject:staff forKey:@"staff"];    [archiver finishEncoding];        // 获取保存的文件名    NSString* pathFile = [self getDocumentDir];    pathFile = [pathFile stringByAppendingPathComponent:@"staff.archi"];        // 保存数据（归档）    [data writeToFile:pathFile atomically:YES];        UIAlertView* alert = [[UIAlertView alloc] initWithTitle:@"Infomation" message:@"Archive finished" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];    [alert show];    [self textClear];}-(IBAction)onArchiverLoad:(id)sender{    // 获取保存的文件名    NSString* pathFile = [self getDocumentDir];    pathFile = [pathFile stringByAppendingPathComponent:@"staff.archi"];        // 读取归档文件到内存（只读）    NSData* data = [NSData dataWithContentsOfFile:pathFile];        // 解码内存数据（只读）    NSKeyedUnarchiver* unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];    Staff* staff = [unarchiver decodeObjectForKey:@"staff"];    [unarchiver finishDecoding];        self._textNickName.text = staff._nickName;    self._textEmail.text = staff._email;    self._textPhone.text = staff._phone;    self._textSex.text = staff._sex;    self._textPosition.text = staff._position;        UIAlertView* alert = [[UIAlertView alloc] initWithTitle:@"Infomation" message:@"Load from Archiver finished" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];    [alert show];}- (void)viewDidLoad{    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end

工程代码