小弟很久没有更新了 最近在往IOS上靠
IOS中的归档 即是我们所知道的序列化和反序列化
我们可以用plist来存储比较简单的数据类型 但是如果我想把自己定义的类型进行持久化呢？
这就要用到序列化了 下面贴代码
先是自定义一个自己的类 需要继承 NSCoding 接口
-------------------------------------//我是分隔线//-----------------------------------------
#import <Foundation/Foundation.h>
@interface FourLines : NSObject <NSCoding,NSCopying> {
}
@property (nonatomic,retain) NSString *field1;
@property (nonatomic,retain) NSString *field2;
@property (nonatomic,retain) NSString *field3;
@property (nonatomic,retain) NSString *field4;
@end
#import "FourLines.h"
#define kField1Key @"Field1"
#define kField2Key @"Field2"
#define kField3Key @"Field3"
#define kField4Key @"Field4"
@implementation FourLines
@synthesize field1;
@synthesize field2;
@synthesize field3;
@synthesize field4;
- (void) encodeWithCoder:(NSCoder *)aCoder{
[aCoder encodeObject:field1 forKey:kField1Key];
[aCoder encodeObject:field2 forKey:kField2Key];
[aCoder encodeObject:field3 forKey:kField3Key];
[aCoder encodeObject:field4 forKey:kField4Key];
}
- (id)initWithCoder:(NSCoder *)aDecoder{
if (self = [super init]) {
field1 = [[aDecoder decodeObjectForKey:kField1Key] retain];
field2 = [[aDecoder decodeObjectForKey:kField2Key] retain];
field3 = [[aDecoder decodeObjectForKey:kField3Key] retain];
field4 = [[aDecoder decodeObjectForKey:kField4Key] retain];
}
return self;
}
- (id)copyWithZone:(NSZone *)zone{
FourLines *copy = [[[self class] allocWithZone:zone] init];
copy.field1 = [[self.field1 copyWithZone:zone] autorelease];
copy.field2 = [[self.field2 copyWithZone:zone] autorelease];
copy.field3 = [[self.field3 copyWithZone:zone] autorelease];
copy.field4 = [[self.field4 copyWithZone:zone] autorelease];
return copy;
}
- (void)dealloc{
[field1 release];
[field2 release];
[field3 release];
[field4 release];
[super dealloc];
}
@end
下面是一个controller 来实现如何持久化自定义类
#import <UIKit/UIKit.h>
//#define kFilename @"data.plist"
#define kFilename @"archive"
#define kDataKey @"Data"
//define kFilename @"dataarchiive.plist"
//#define kDataKey @"Data"
//#define kFilename @"data.sqlite3"
@interface PersistenceViewController : UIViewController {
}
@property (nonatomic,retain) IBOutlet UITextField *field1;
@property (nonatomic,retain) IBOutlet UITextField *field2;
@property (nonatomic,retain) IBOutlet UITextField *field3;
@property (nonatomic,retain) IBOutlet UITextField *field4;
- (NSString *)dataFilePath;
- (void)applicationWillResignActive:(NSNotification *)notification;
@end
#import "PersistenceViewController.h"
#import "FourLines.h"
@implementation PersistenceViewController
@synthesize field1;
@synthesize field2;
@synthesize field3;
@synthesize field4;
- (NSString *)dataFilePath{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSLog(@"Document Path:%@",documentsDirectory);
return [documentsDirectory stringByAppendingPathComponent:kFilename];
}
/*
// The designated initializer. Override to perform setup that is required before the view is loaded.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
*/
/*
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
}
*/
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
NSString *filePath = [self dataFilePath];
if ([[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
/*
NSArray *array = [[NSArray alloc] initWithContentsOfFile:filePath];
field1.text = [array objectAtIndex:0];
field2.text = [array objectAtIndex:1];
field3.text = [array objectAtIndex:2];
field4.text = [array objectAtIndex:3];
[array release];
*/
//encoding
NSData *data = [[NSMutableData alloc] initWithContentsOfFile:filePath];
NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
FourLines *fourLines = [unarchiver decodeObjectForKey:kDataKey];
[unarchiver finishDecoding];
field1.text = fourLines.field1;
field2.text = fourLines.field2;
field3.text = fourLines.field3;
field4.text = fourLines.field4;
[unarchiver release];
[data release];
}
UIApplication *app = [UIApplication sharedApplication];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationWillResignActive:) name:UIApplicationWillResignActiveNotification object:app];
[super viewDidLoad];
}
- (void) applicationWillResignActive:(NSNotification *)notification{
/*
NSMutableArray *array = [[NSMutableArray alloc] init];
[array addObject:field1.text];
[array addObject:field2.text];
[array addObject:field3.text];
[array addObject:field4.text];
[array writeToFile:[self dataFilePath] atomically:YES];
*/
FourLines *fourLine = [[FourLines alloc] init];
fourLine.field1 = field1.text;
fourLine.field2 = field2.text;
fourLine.field3 = field3.text;
fourLine.field4 = field4.text;
NSMutableData *data = [[NSMutableData alloc] init];
NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
[archiver encodeObject:fourLine forKey:kDataKey];
[archiver finishEncoding];
[data writeToFile:[self dataFilePath] atomically:YES];
[fourLine release];
[data release];
[archiver release];
}
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return YES;
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[field1 release];
[field2 release];
[field3 release];
[field4 release];
[super dealloc];
}
@end
希望能对您有帮助 下次分享如何使用嵌入式数据库 sqlite3
