IOS学习笔记二十三对象归档(NSKeyedArchiver、NSKeyedUnArchiver、NSCodeing)

1、NSKeyedArchiver、NSKeyedUnArchiver

1）、archiveRootObject:toFile 归档对象到这个路径文件

2）、unarchiveObjectWithFile:从这个路径文件把对象进行恢复

对象归档这里我们可以理解Android里面的序列化，就是把对象保存到文件持久化，Android里面进行持久化的必须实现Serializable和Parcelable，然后IOS里面持久化必须实现NSCodeing协议，IOS进行持久化操作一般需要NSKeyedArchiver实现。

 

 

 

2、NSCodeing协议

1）、initWithCoder：该方法恢复对象

2）、encodeWithCoder：归档该对象

 

 

 

3、测试Demo(把Dictionary和普通对象进行对象归档)

IApple.h

#import <Foundation/Foundation.h> #ifndef IApple_h #define IApple_h @interface IApple : NSObject <NSCoding> @property (nonatomic, copy) NSString *color; @property (nonatomic, assign) double weight; @property (nonatomic, assign) int size; -(id)initWithColor:(NSString *) color weight:(double) weight size:(int) size; @end#endif /* IApple_h */

 

IApple.m

#import "IApple.h" #import <Foundation/Foundation.h> @implementation IApple @synthesize color = _color; @synthesize weight = _weight; @synthesize size = _size; -(id)initWithColor:(NSString *) color weight:(double) weight size:(int) size {if (self = [super init]){self.color = color;self.weight = weight;self.size = size;}return self; } -(NSString *)description {return [NSString stringWithFormat:@"<IApple [color = %@, weight = %g, _size = %d]>", self.color, self.weight, self.size]; }-(void)encodeWithCoder:(NSCoder *)aCoder {[aCoder encodeObject:_color forKey:@"color"];[aCoder encodeDouble:_weight forKey:@"weight"];[aCoder encodeInt:_size forKey:@"size"]; } -(id) initWithCoder:(NSCoder *)aDecoder {_color = [aDecoder decodeObjectForKey:@"color"];_weight = [aDecoder decodeDoubleForKey:@"weight"];_size = [aDecoder decodeIntForKey:@"size"];return self; }@end

 

main.m

#import "IApple.h" int main(int argc, char * argv[]) {@autoreleasepool {//在document目录下创建一个chenyu.txt空文件NSArray *docPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);NSString *path = [docPaths objectAtIndex:0];NSLog(@"document path:%@", path);NSFileManager *fileManager = [NSFileManager defaultManager];NSString *chenyuPath = [path stringByAppendingPathComponent:@"chenyu.txt"];BOOL isSuccess = [fileManager createFileAtPath:chenyuPath contents:nil attributes:nil];if (isSuccess) {NSLog(@"make chenyu.txt success");} else {NSLog(@"make chenyu.txt fail");}//用NSKeyedArchiver进行对象归档NSDictionary *dic = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithInt:10], @"oc", [NSNumber numberWithInt:20], @"java", [NSNumber numberWithInt:30], @"c++", nil];[NSKeyedArchiver archiveRootObject:dic toFile:chenyuPath];NSLog(@"123");//利用NSKeyedUnarchiver进行恢复对象NSDictionary *dic1 = [NSKeyedUnarchiver unarchiveObjectWithFile:chenyuPath];NSLog(@"oc value is %@", [dic1 valueForKey:@"oc"]);NSLog(@"java value is %@", [dic1 valueForKey:@"java"]);NSLog(@"c++ value is %@", [dic1 valueForKey:@"c++"]);//我们先看下chenyu.txt是什么文件，我们用file命令看下 file chenyu.txt,发现是二进制文件 // file chenyu.txt // chenyu.txt: Apple binary property list//下面为chenyu.txt文件的内容，我是用vim打开的 // bplist00Ô^A^B^C^D^E^F^Z^[X$versionX$objectsY$archiverT$top^R^@^A<86> ¥^G^H^Q^R^SU$nullÓ // ^K^L^N^PWNS.keysZNS.objectsV$class¡^M<80>^B¡^O<80>^C<80>^DRoc^P Ò^T^U^V^WZ$classnameX$classes\NSDictionary¢^X^Y\NSDictionaryXNSObject_^P^ONSKeyedArchiverÑ^\^]Troot<80>^A^H^Q^Z#-27=CJR]dfhjlnqsx<83><8c><99><9c>©²ÄÇÌ^@^@^@^@^@^@^A^A^@^@^@^@^@^@^@^^^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@Î//我们再用chenyu.txt归档IApple对象IApple *apple = [[IApple alloc] initWithColor:@"red" weight:5.6 size:20];IApple *apple1 = [[IApple alloc] initWithColor:@"wihte" weight:6.6 size:30];//用NSKeyedArchiver进行IApple对象归档[NSKeyedArchiver archiveRootObject:apple toFile:chenyuPath];[NSKeyedArchiver archiveRootObject:apple1 toFile:chenyuPath];IApple *saveApple = [NSKeyedUnarchiver unarchiveObjectWithFile:chenyuPath];NSLog(@"saveApple is %@", saveApple);} }

 

 

 

 

 

4、运行结果

2018-07-22 00:08:57.804831+0800 cyTest[37026:15851965] document path:/Users/ls/Library/Developer/CoreSimulator/Devices/3FF9B833-FAF8-4C30-A855-3D40A4EAE8A6/data/Containers/Data/Application/272166E9-67BC-4E6B-B79A-0FF9DA389D7D/Documents 2018-07-22 00:08:57.810379+0800 cyTest[37026:15851965] make chenyu.txt success 2018-07-22 00:08:57.813994+0800 cyTest[37026:15851965] 123 2018-07-22 00:08:57.815001+0800 cyTest[37026:15851965] oc value is 10 2018-07-22 00:08:57.815228+0800 cyTest[37026:15851965] java value is 20 2018-07-22 00:08:57.815438+0800 cyTest[37026:15851965] c++ value is 30 2018-07-22 00:08:57.822014+0800 cyTest[37026:15851965] saveApple is <IApple [color = wihte, weight = 6.6, _size = 30]>

 

 

5、问题思考

是不是每次只能保持一个对象到文件里面呢?暂时感觉是这样的，后面遇到问题再分析。

 

 

总结

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