iPhone开发【二十二】数据持久化总结之第3篇—归档（NSKeyedArchiver、NSKeyedUnarchiver）

转载请注明出处，原文网址：http://blog.csdn.net/m_changgong/article/details/8284135 作者：张燕广

实现的功能：1）演示使用归档持久化数据。

关键词：数据持久化 归档  NSKeyedArchiver NSKeyedUnarchiver

1、将上一篇iPhone开发【二十一】数据持久化总结之第2篇属性文件（.plist）的工程拷贝一份，名称修改为Persistence-archiver，工程结构如下：

2、添加Person.h类，如下：

Person.h：

 #import <Foundation/Foundation.h>

 @interface Person : NSObject<NSCoding,NSCopying>
 @property(nonatomic,retain)NSString *name;
 @property(nonatomic,retain)NSString *gender;
 @property(nonatomic,retain)NSString *age;
 @property(nonatomic,retain)NSString *education;
 @end

Person.m：

 #import "Person.h"
 #define kNameKey        @"name"
 #define kGenderKey      @"gender"
 #define kAgeKey         @"age"
 #define kEducationKey   @"education"
 @implementation Person
 @synthesize name,gender,age,education;

 #pragma mark -
 #pragma mark NSCoding
 -(void)encodeWithCoder:(NSCoder *)aCoder{//编码
     [aCoder encodeObject:name forKey:kNameKey];
     [aCoder encodeObject:gender forKey:kGenderKey];
     [aCoder encodeObject:age forKey:kAgeKey];
     [aCoder encodeObject:education forKey:kEducationKey];
 }

 -(id)initWithCoder:(NSCoder *)aDecoder{//解码
     if(self == [super init]){
         name = [[aDecoder decodeObjectForKey:kNameKey]retain];
         gender = [[aDecoder decodeObjectForKey:kGenderKey]retain];
         age = [[aDecoder decodeObjectForKey:kAgeKey]retain];
         education = [[aDecoder decodeObjectForKey:kEducationKey]retain];
     }
     return self;
 }

 #pragma mark -
 #pragma mark NSCopying
 -(id)copyWithZone:(NSZone *)zone{
     Person *person = [[[self class]allocWithZone:zone]init];
     person.name = [[self.name copyWithZone:zone]autorelease];
     person.gender = [[self.gender copyWithZone:zone]autorelease];
     person.name = [[self.name copyWithZone:zone]autorelease];
     person.name = [[self.name copyWithZone:zone]autorelease];
     return person;
 }

 @end

3、接下来主要修改ViewController

ViewController.h，主要是修改了宏，如下：

 <span style="font-size:18px;">//#define kFileName @"data.plist"
 #define kFileName @"archive"
 #define kDataKey @"Data"

 #import <UIKit/UIKit.h>

 @interface ViewController : UIViewController
 @property(nonatomic,retain)IBOutlet UITextField *name;
 @property(nonatomic,retain)IBOutlet UITextField *gender;
 @property(nonatomic,retain)IBOutlet UITextField *age;
 @property(nonatomic,retain)IBOutlet UITextField *education;

 -(NSString *)dataFilePath;
 -(void)applicationWillResignActive:(NSNotification *)nofication;

 @end</span>

主要修改了ViewController.m，如下：

 <span style="font-size:18px;">#import "ViewController.h"
 #import "Person.h"

 @implementation ViewController
 @synthesize name,gender,age,education;

 -(NSString *)dataFilePath{
     NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);
     NSString *documentsDirectory = [paths objectAtIndex:0];
     return [documentsDirectory stringByAppendingPathComponent:kFileName];
 }

 - (void)didReceiveMemoryWarning
 {
     [super didReceiveMemoryWarning];
     // Release any cached data, images, etc that aren't in use.
 }

 #pragma mark - View lifecycle

 - (void)viewDidLoad
 {
     // Do any additional setup after loading the view, typically from a nib.
     NSString *filePath = [self dataFilePath];
     NSLog(@"filePath=%@",filePath);

     if([[NSFileManager defaultManager] fileExistsAtPath:filePath]){
         //属性列表
         /*
         NSArray *array = [[NSArray alloc]initWithContentsOfFile:filePath];
         name.text = [array objectAtIndex:0];
         gender.text = [array objectAtIndex:1];
         age.text = [array objectAtIndex:2];
         education.text = [array objectAtIndex:3];

         [array release];*/

         NSData *data = [[NSMutableData alloc]initWithContentsOfFile:[self dataFilePath]];
         NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc]initForReadingWithData:data];
         Person *person = [unarchiver decodeObjectForKey:kDataKey];
         [unarchiver finishDecoding];

         name.text = person.name;
         gender.text = person.gender;
         age.text = person.age;
         education.text = person.education;

         [unarchiver release];
         [data release];
     }

     UIApplication *app = [UIApplication sharedApplication];
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationWillResignActive:) name:UIApplicationWillResignActiveNotification object:app];

     [super viewDidLoad];
 }

 -(void)applicationWillResignActive:(NSNotification *)nofication{

     //属性列表
     /*
     NSMutableArray *array = [[NSMutableArray alloc]init];
     [array addObject:name.text];
     [array addObject:gender.text];
     [array addObject:age.text];
     [array addObject:education.text];
     [array writeToFile:[self dataFilePath] atomically:YES];
     [array release];*/

     Person *person = [[Person alloc]init];
     person.name = name.text;
     person.gender = gender.text;
     person.age = age.text;
     person.education = education.text;

     NSMutableData *data = [[NSMutableData alloc]init];
     NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc]initForWritingWithMutableData:data];
     [archiver encodeObject:person forKey:kDataKey];
     [archiver finishEncoding];

     [data writeToFile:[self dataFilePath] atomically:YES];
     [person release];
     [archiver release];
     [data release];
 }

 - (void)viewDidUnload
 {
     [super viewDidUnload];
     // Release any retained subviews of the main view.
     // e.g. self.myOutlet = nil;
     self.name = nil;
     self.gender = nil;
     self.age = nil;
     self.education = nil;
 }

 -(void)dealloc{
     [name release];
     [gender release];
     [age release];
     [education release];
 }

 - (void)viewWillAppear:(BOOL)animated
 {
     [super viewWillAppear:animated];
 }

 - (void)viewDidAppear:(BOOL)animated
 {
     [super viewDidAppear:animated];
 }

 - (void)viewWillDisappear:(BOOL)animated
 {
     [super viewWillDisappear:animated];
 }

 - (void)viewDidDisappear:(BOOL)animated
 {
     [super viewDidDisappear:animated];
 }

 - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
 {
     // Return YES for supported orientations
     return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
 }

 @end</span>

4、通过iPhone开发【二十】数据持久化总结之第1篇NSUserDefaults 可以知道保存数据archive文件的存储位置是：

 /Users/duobianxing/Library/Application Support/iPhone Simulator/5.0/Applications/F694104D-894D-4230-A01B-C62066B3DEC8/Documents

5、总结：

与属性列表相比，归档可以写入复杂的对象（Person类的实例）。

需要源码的网友请留言哦