ObjcetiveC 归档 迎客

对于基本Objective-C类对象(NSString,NSArray...):

方法一：使用XML属性列表进行归档。

  NSDictionary *glossay;
  //存
   glossay = [NSDictionary dictionaryWithObjectsAndKeys:@"obj val 1",@"key1",@"obj val 2",@"key2",nil];
  if ([glossay writeToFile:@"glossary" atomically:YES] == NO) {
    NSLog(@"Save to file failed!");
  }

  //取
   glossay = [NSDictionary dictionaryWithContentsOfFile:@"glossary"];
  
  NSLog(@"%@",[glossay valueForKey:@"key2"]);

方法二：使用NSKeyedArchiver归档。

  NSDictionary *glossay;
  glossay = [NSDictionary dictionaryWithObjectsAndKeys:@"obj val 1",@"key1",@"obj val 2",@"key2",nil];
  //存
  if ([NSKeyedArchiver archiveRootObject:glossay toFile:@"glossay.archiver"] == NO) {
    NSLog(@"write file fail!!");
  }
  
  //取
  glossay = [NSKeyedUnarchiver unarchiveObjectWithFile:@"glossay.archiver"];
  NSLog(@"%@",[glossay valueForKey:@"key2"]);

对于自定义的Class，需要实现NSCoding协议，然后用上述方法二归档：

//TestProperty.h
 #import <Cocoa/Cocoa.h>


@interface TestProperty : NSObject <NSCopying,NSCoding>{
  NSString *name;
  NSString *password;
  NSMutableString *interest;
  NSInteger myInt;
}

@property (retain,nonatomic) NSString *name,*password;
@property (retain,nonatomic) NSMutableString *interest;
@property NSInteger myInt;

 -(void) rename:(NSString *)newname;

@end

====================
//TestProperty.m

#import "TestProperty.h"


@implementation TestProperty

@synthesize name,password,interest;
@synthesize myInt;

-(void) rename:(NSString *)newname{
  // 这里可以直接写成
  // self.name = newname;
  //
  if (name != newname) {
    [name autorelease];
    name = newname;
    [name retain];
  }
}

-(void) dealloc{
  self.name = nil;
  self.password = nil;
  self.interest = nil;
  [super dealloc];
}
- (id)copyWithZone:(NSZone *)zone{
  TestProperty *newObj = [[[self class] allocWithZone:zone] init];
  newObj.name = name;
  newObj.password = password;
  newObj.myInt = myInt;
  //深复制
  NSMutableString *tmpStr = [interest mutableCopy];
  newObj.interest = tmpStr;
  [tmpStr release];
  
  //浅复制
  //newObj.interest = interest;
  return newObj;
}

- (void)encodeWithCoder:(NSCoder *)aCoder{
  //如果是子类，应该加上：
  //[super encodeWithCoder:aCoder];
  
  //注意这里如何处理对象的（其实是实现了NSCoding的类）！
  [aCoder encodeObject:name forKey: @"TestPropertyName"];
  [aCoder encodeObject:password forKey:@"TestPropertyPassword"];
  [aCoder encodeObject:interest forKey:@"TestPropertyInterest"];
  
  //注意这里如何处理基本类型！
  [aCoder encodeInt:myInt forKey:@"TestPropertyMyInt"];
  
}

- (id)initWithCoder:(NSCoder *)aDecoder{
  //如果是子类，应该加上：
  //self = [super initWithCoder:aDecoder];
  
  //解码对象
  name = [[aDecoder decodeObjectForKey:@"TestPropertyName"] retain];
  password = [[aDecoder decodeObjectForKey:@"TestPropertyPassword"] retain];
  interest = [[aDecoder decodeObjectForKey:@"TestPropertyInterest"] retain];
  
  //解码基本类型
  myInt = [aDecoder decodeIntForKey:@"TestPropertyMyInt"];
  return self;
}
@end

===============
//测试

  //存
  TestProperty *test = [[TestProperty alloc] init];
  test.name = @"pxl";
  test.password = @"pwd...";
  test.interest = [NSMutableString stringWithString:@"interest..."];
  test.myInt = 123;
  if([NSKeyedArchiver archiveRootObject:test toFile:@"testproerty.archive"] == NO){
    NSLog(@"write to file fail!!");
  }
  
  //取
  TestProperty *test = [NSKeyedUnarchiver unarchiveObjectWithFile:@"testproerty.archive"];
  NSLog(@"%@",test.name);

使用NSData创建定义档案。

以上面已实现NSCoding协议的TestProperty类为例。

  //存
   TestProperty *test = [[TestProperty alloc] init];
  test.name = @"pxl";
  test.password = @"pwd...";
  test.interest = [NSMutableString stringWithString:@"interest..."];
  test.myInt = 123;
  
  NSMutableData *dataArea = [NSMutableData data];
  NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:dataArea];
  [archiver encodeObject:test forKey:@"testObj"];
  
  //这里还可以加其它的对象
  //......
   
  [archiver finishEncoding];
  
  if ([dataArea writeToFile:@"test.archiver" atomically:YES] == NO) {
    NSLog(@"write to file fail...");
  }
  
  [archiver release];
  [test release];

 ============

    //取
   NSData *dataArea = [NSData dataWithContentsOfFile:@"test.archiver"];
  if(!dataArea){
    NSLog(@"Can't read back archive file");
    return (1);
  }
  
  NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:dataArea];  
  TestProperty *test = [unarchiver decodeObjectForKey:@"testObj"];
  [unarchiver finishDecoding];
  
  NSLog(@"%@",test.name);
  [unarchiver release];

利用归档实现对象深复制：

  //先删除TestProperty类中实现的NSCopying协议代码。
   
  TestProperty *test = [[TestProperty alloc] init];
  test.name = @"pxl";
  test.password = @"pwd...";
  test.interest = [NSMutableString stringWithString:@"interest..."];
  test.myInt = 123;
  
  //对test进行深复制
   NSData *data =  [NSKeyedArchiver archivedDataWithRootObject:test];
  TestProperty *test2 = [NSKeyedUnarchiver unarchiveObjectWithData:data];
  
  [test2.interest appendString:@"film"];
  NSLog(@"%@",test.interest);
  NSLog(@"%@",test2.interest);

  //输出
   2010-12-30 16:11:47.391 HelloWorld[4599:a0f] interest...
  2010-12-30 16:11:47.393 HelloWorld[4599:a0f] interest...film