1.創建一個單例模式

//

//  ios24_saveObjectToFileViewController.h

//  ios24-saveObjectToFile

//

//  Created by  on 13-6-18.

//  Copyright 2013年 __MyCompanyName__. All rights reserved.

//

 

#import <UIKit/UIKit.h>

 

@interface 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.

//  Copyright 2013年 __MyCompanyName__. All rights reserved.

//

 

#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

//保存數據

-(IBAction)save{

//實現保存

    NSString *savePath=[self getFilePath];

    //定義data

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

    //定義壓縮的工具類

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

    //保存的對象

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

    stu.studentId=tfId.text;

    stu.studentName=tfName.text;

    stu.studentClass=tfClass.text;

    //壓縮

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

    [archer finishEncoding];

    //寫入文件

    [data writeToFile:savePath atomically:YES];

    NSLog(@"保存成功");

   
   
}

//讀取數據

-(IBAction)read{

    //獲取path

    NSString *readPath=[self getFilePath];

    //獲取文件的二進制流

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

    if (data.length>0) {

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

        //完成student對象的實例化

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

        [unArchiver finishDecoding];

        //設置顯示

        tfId.text=stu.studentId;

        tfName.text=stu.studentName;

        tfClass.text=stu.studentClass;

 

    }

    //進行解壓

   
}

//

-(NSString *)getFilePath{

    //設置文件保存的路徑

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

   
    //獲取documents路徑

    NSString *documentPath = [paths lastObject];

    //定義全路徑

    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)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

{

    // Return YES for supported orientations

    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);

}

 

@end

 

2.建立一個student類

//

//  Student.h

//  ios24-saveObjectToFile

//

//  Created by  on 13-6-18.

//  Copyright 2013年 __MyCompanyName__. All rights reserved.

//

 

#import <Foundation/Foundation.h>

//要實現當前類對象，就必須實現nscoding協議

@interface 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.

//  Copyright 2013年 __MyCompanyName__. All rights reserved.

//

 

#import "Student.h"

 

@implementation Student

@synthesize studentId,studentName,studentClass;

//進行歸檔編碼

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

    //將屬性

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

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

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

}

//對對象進行讀取讀取出來

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

    //進行屬性解碼

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

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

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

    return self;

}

@end