Ios24-data persistence-object Archiving

1. Create a singleton Mode

//

// Ios24_saveObjectToFileViewController.h

// Ios24-saveObjectToFile

//

// Created by on 13-6-18.

// Copyright 2013 _ 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 _ 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

// Save data

-(IBAction) save {

// Save

NSString * savePath = [self getFilePath];

// Define data

NSMutableData * data = [NSMutableData alloc] init];

// Define the compressed tool class

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

// Saved object

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

Stu. studentId = tfId. text;

Stu. studentName = tfName. text;

Stu. studentClass = tfClass. text;

// Compression

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

[Archer finishEncoding];

// Write a file

[Data writeToFile: savePath atomically: YES];

NSLog (@ "saved successfully ");

}

// Read data

-(IBAction) read {

// Obtain the path

NSString * readPath = [self getFilePath];

// Obtain the binary stream of the object

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

If (data. length> 0 ){

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

// Instantiate the student object

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

[UnArchiver finishDecoding];

// Set display

TfId. text = stu. studentId;

TfName. text = stu. studentName;

TfClass. text = stu. studentClass;

 

}

// Decompress the package

}

//

-(NSString *) getFilePath {

// Set the path for saving the file

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

// Obtain the sources path

NSString * documentPath = [paths lastObject];

// Define the full path

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. Create a student class

//

// Student. h

// Ios24-saveObjectToFile

//

// Created by on 13-6-18.

// Copyright 2013 _ MyCompanyName _. All rights reserved.

//

 

# Import <Foundation/Foundation. h>

// To implement the current class object, the nscoding protocol must be implemented.

@ 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 _ MyCompanyName _. All rights reserved.

//

 

# Import "Student. h"

 

@ Implementation Student

@ Synthesize studentId, studentName, studentClass;

// Perform archive Encoding

-(Void) encodeWithCoder :( NSCoder *) ACO {

// Set attributes

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

[ACO der encodeObject: studentName forKey: @ "studentName"];

[ACO der encodeObject: studentClass forKey: @ "studentClass"];

}

// Read the object

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

// Perform attribute Decoding

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

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

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

Return self;

}

@ End