ios24-数据持久化-对象归档

1.创建一个单例模式

// ios24_saveObjectToFileViewController.h

// ios24-saveObjectToFile

// Created by on 13-6-18.

#import <UIKit/UIKit.h>

@inte易做图ce ios24_saveObjectToFileViewController : UIViewController<UITextFieldDelegate>

{

UITextField *tfId;

UITextField *tfName;

UITextField *tfClass;

}

@property (nonatomic,retain) IBOutlet UITextField *tfId;

@property (nonatomic,retain) IBOutlet UITextField *tfName;

@property (nonatomic,retain) IBOutlet UITextField *tfClass;

-(IBAction)save;

-(IBAction)read;

-(NSString *)getFilePath;

@end

----------------------------------------------

// ios24_saveObjectToFileViewController.m

// ios24-saveObjectToFile

// Created by on 13-6-18.

#import "ios24_saveObjectToFileViewController.h"

#import "Student.h"

@implementation ios24_saveObjectToFileViewController

@synthesize tfId,tfName,tfClass;

- (void)didReceiveMemoryWarning

{

[super didReceiveMemoryWarning];

// Release any cached data, images, etc that aren't in use.

}

#pragma mark - View lifecycle

//保存数据

-(IBAction)save{

//实现保存

NSString *savePath=[self getFilePath];

//定义data

NSMutableData *data=[[NSMutableData alloc]init ];

//定义压缩的工具类

NSKeyedArchiver *archer=[[NSKeyedArchiver alloc]initForWritingWithMutableData:data];

//保存的对象

Student *stu=[[Student alloc]init];

stu.studentId=tfId.text;

stu.studentName=tfName.text;

stu.studentClass=tfClass.text;

//压缩

[archer encodeObject:stu forKey:@"stuobj"];

[archer finishEncoding];

//写入文件

[data writeToFile:savePath atomically:YES];

NSLog(@"保存成功");

}

//读取数据

-(IBAction)read{

//获取path

NSString *readPath=[self getFilePath];

//获取文件的二进制流

NSData *data=[[NSData alloc]initWithContentsOfFile:readPath];

if (data.length>0) {

NSKeyedUnarchiver *unArchiver=[[NSKeyedUnarchiver alloc]initForReadingWithData:data];

//完成student对象的实例化

Student *stu=[unArchiver decodeObjectForKey:@"stuobj"];

[unArchiver finishDecoding];

//设置显示

tfId.text=stu.studentId;

tfName.text=stu.studentName;

tfClass.text=stu.studentClass;

}

//进行解压

}

-(NSString *)getFilePath{

//设置文件保存的路径

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

//获取documents路径

NSString *documentPath = [paths lastObject];

//定义全路径

NSString *savePath = [documentPath stringByAppendingPathComponent:@"student.achiver"];

return savePath;

}

- (BOOL)textFieldShouldReturn:(UITextField *)textField{

[textField resignFirstResponder];

return YES;

}

- (void)viewDidLoad

{

[super viewDidLoad];

tfId.delegate=self;

tfName.delegate=self;

tfClass.delegate=self;

// Do any additional setup after loading the view, typically from a nib.

}

- (void)viewDidUnload

{

[super viewDidUnload];

// Release any retained subviews of the main view.

// e.g. self.myOutlet = nil;

}

- (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)shouldAutorotateToInte易做图ceOrientation:(UIInte易做图ceOrientation)inte易做图ceOrientation

{

// Return YES for supported orientations

return (inte易做图ceOrientation != UIInte易做图ceOrientationPortraitUpsideDown);

}

@end

2.建立一个student类

// Student.h

// ios24-saveObjectToFile

// Created by on 13-6-18.

#import <Foundation/Foundation.h>

//要实现当前类对象，就必须实现nscoding协议

@inte易做图ce Student : NSObject<NSCoding>

{

NSString *studentId;

NSString *studentName;

NSString *studentClass;

}

@property (nonatomic,retain) NSString *studentId;

@property (nonatomic,retain) NSString *studentName;

@property (nonatomic,retain) NSString *studentClass;

@end

------------------------------

// Student.m

// ios24-saveObjectToFile

// Created by on 13-6-18.

#import "Student.h"

@implementation Student

@synthesize studentId,studentName,studentClass;

//进行归档编码

-(void)encodeWithCoder:(NSCoder *)aCoder{

//将属性

[aCoder encodeObject:studentId forKey:@"studentId"];

[aCoder encodeObject:studentName forKey:@"studentName"];

[aCoder encodeObject:studentClass forKey:@"studentClass"];

}

//对对象进行读取读取出来

-(id)initWithCoder:(NSCoder *)aDecoder{

//进行属性解码

self.studentId=[aDecoder decodeObjectForKey:@"studentId"];

self.studentName=[aDecoder decodeObjectForKey:@"studentName"];

补充：移动开发 , IOS ,