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标题: 详解Objective-C归档问题解决 [打印本页]

作者: 602516169 时间: 2016-8-28 07:01
标题: 详解Objective-C归档问题解决
Objective-C归档问题解决是本文要将诶少的内容，主要是来学习在Objective-C如何来归档，本文很详细的解决了这一问题，来看详细内容。

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。

代码

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。

代码

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：

代码

//TestProperty.h
  #import <Cocoa/Cocoa.h>
@interface TestProperty : NSObject <NSCopying,NSCoding>{
  NSString *name;
  NSString *password;
NSMutableString *interest;
  NSInteger myInt;
}
  12 @property (retain,nonatomic) NSString *name,*password;
@property (retain,nonatomic) NSMutableString *interest;
@property NSInteger myInt;
-(void) rename:(NSString *)newname;
@end
====================
//TestProperty.m
  23 #import "TestProperty.h"
  25  26 @implementation TestProperty
  28 @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，代码

//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13 //......
[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：

代码

//先删除TestProperty类中实现的NSCopying协议代码。
TestProperty *test = [[TestProperty alloc] init];
test.name = @"pxl";
est.password = @"pwd...";
test.interest = [NSMutableString stringWithString:@"interest..."];
test.myInt = 123;
//对test进行深复制10 NSData *data =  [NSKeyedArchiver archivedDataWithRootObject:test];11
               TestProperty *test2 = [NSKeyedUnarchiver unarchiveObjectWithData:data];
[test2.interest appendString:@"film"];
NSLog(@"%@",test.interest);15 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
小结：详解Objective-C归档问题解决的内容介绍完了，希望通过本文的学习能对你有所帮助！

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