实现NSCoding协议
1.例子：
AddressCard.h接口文件
#import<Foundation/Foundation.h>
@interface AddressCard:NSObject<NSCoding,NSCoping>
@property (copy,nonatomic) NSString *name,email;
-(void)setName:(NSString) *theName andEmail:(NSString *)theEmail;
-(NSComparisonResult) compareNames:(id)element;
-(void)print;
AddressCard.m文件
-(void)encodeWithCoder :(NSCoder *)decoder
{
[encoder encodeObject:name forKey:@"AddressCardName"];
[encoder encodeObject:email forKey:@"AddressCardEmail"];
// [encoder encodeBool:YES forKey:@"BoolValue"];
}
-(void)initWithCoder :(NSCoder *)decoder
{
name = [decoder decodeObjectforKey:@"AddressCardName"];
email = [decoder decodeObjectforKey:@"AddressCardEmail"];
// boolValue = [decoder decodeBoolforKey:@"BoolValue"];
return self;
}
使用：
if(NSKeyedArchiver archiveRootObject:myBook toFile:@"addrbook.arch"] == NO)
NSLog(@"archiving failed");
AddressBook *mybook = [NSKeyedUnarchiver unarchiveObjectWithFile:@"addrbook.arch"];
2.将两个对象（均实现NSCoding协议）归档到同一文件
#import "AddressBook.h"
#import "Foo.h"
int main(int argc, char *argv[])
{
@autoreleasepool{
Foo *myFool1 = [Foo alloc]init];
NSMutableData *dataArea;
NSKeyedArchiver *archiver;
AddressBook *myBook;
//该处省略了为myFool1和myBook赋值
//设置数据区，并将其连接到一个NSKeyedArchiver对象
dataArea = [NSMutableData data];
archiver = [[NSKeyedArchiver alloc] initForWritingWithMutaleData:dataArea];
//现在可以开始存档对象
[archiver encodeObject:myBook forKey:@"myaddrbook"];
[archiver encodeObject:myFool1 forKey:@"myfool1"];
[archiver finishEncoding];
//将存档的数据写入文件
if([dataArea writeToFile:@"myArchive" atomically :YES] == NO)
NSLog(@"Archiving failed!");
}
return 0;
}
解析
#import "AddressBook.h"
#import"Foo.h"
int main(int argc, char *argv[])
{
@autoreleasepool{
NSData *dataArea;
NSKeyedUnarchiver *unarchiver;
Foo *myFoo1;
AddressBook *myBook;
//从归档文件读取并连接
//NSkeyedUnarchiver 对象
dataArea = [NSData dataWithContentsOfFile:@"myArchive"];
if(!dataArea){
NSLog(@"Can't read back archive file!");
return 1;
}
unarchiver = [[NSKeyedUnarchiver alloc]initForReadingData:dataArea];
//解码以前储存在归档文件中的对象
myBook = [unarchiver decodeObjectForKey:@"myaddrbook"];
myFoo1 = [unarchiver decodeObjectForKey:@"myfoo1"];
[unarchiver finishDecoding];
//验证是否还原成功
[myBook list];
NSLog(@%@\n%i\n%g),[myFoo1 strVal],[myFoo1 intVal],[myFoo1 floatVal]);
}
return 0;
}
3.对与实现了NSCoding协议的对象，可以使用归档深复制对象：
NSMutableArray *dataArray = [NSMutableArray arrayWithObjects:[NSMutableString stringWithString:@"one"],[NSMutableString stringWithString:@"two"],[NSMutableString stringWithString:@"thress"],nil];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:dataArray];
NSMutableArray *dataArray2 = [NSKeyedUnarchiver unarchiveObjectWithData:data];
NSMutableString *mStr = [dataArray2 objectAtIndex:0];
[mStr appendString@"ONE"];
输出
dataArray：
one
two
three
dataArray2：
oneONE
two
three
