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iOS 各种系统文件目录 临时,缓存,document,lib,归档,序列化

Java代码 复制代码 收藏代码
  1. /** 
  2.     1:Documents:应用中用户数据可以放在这里,iTunes备份和恢复的时候会包括此目录 
  3.     2:tmp:存放临时文件,iTunes不会备份和恢复此目录,此目录下文件可能会在应用退出后删除 
  4.     3:Library/Caches:存放缓存文件,iTunes不会备份此目录,此目录下文件不会在应用退出删除 
  5.      */  
  6.     NSArray *paths1=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory  
  7.                                                        , NSUserDomainMask  
  8.                                                        , YES);  
  9.       
  10.       
  11.     NSString *documentsDirect=[paths1 objectAtIndex:0];  
  12.     assert(1 == paths1.count);  
  13.     NSLog(@">>documentsDirect=%@",documentsDirect);  
  14.    
  15.     NSArray *Librarypaths =  NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSDocumentDirectory, YES);  
  16.     NSString* libraryDirectory  = [Librarypaths objectAtIndex:0];  
  17.     NSLog(@">>Librarypaths.length =%d",[Librarypaths count]);  
  18.      assert(1 < Librarypaths.count);  
  19.        
  20.     NSLog(@"libraryDirectory=%@",libraryDirectory);  
  21.       
  22.     //如果要指定其他文件目录,比如Caches目录,需要更换目录工厂常量,上面代码其他的可不变  
  23.     NSArray *pathcaches=NSSearchPathForDirectoriesInDomains(NSCachesDirectory  
  24.                                                        , NSUserDomainMask  
  25.                                                        , YES);  
  26.     NSString* cacheDirectory  = [pathcaches objectAtIndex:0];  
  27.     NSLog(@"cacheDirectory=%@",cacheDirectory);  
  28.     /** 
  29.      使用NSSearchPathForDirectoriesInDomains只能定位Caches目录和Documents目录。 
  30.       
  31.      tmp目录,不能按照上面的做法获得目录了,有个函数可以获得应用的根目录 
  32.      */  
  33.     NSString *tempDir1=NSHomeDirectory() ;  
  34.     NSString *tempDir2=NSTemporaryDirectory();  
  35.     NSLog(@"tempDir1=%@",tempDir1);  
  36.     NSLog(@"tempDir2=%@",tempDir2);  
/**    1:Documents:应用中用户数据可以放在这里,iTunes备份和恢复的时候会包括此目录    2:tmp:存放临时文件,iTunes不会备份和恢复此目录,此目录下文件可能会在应用退出后删除    3:Library/Caches:存放缓存文件,iTunes不会备份此目录,此目录下文件不会在应用退出删除     */    NSArray *paths1=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory                                                       , NSUserDomainMask                                                       , YES);            NSString *documentsDirect=[paths1 objectAtIndex:0];    assert(1 == paths1.count);    NSLog(@">>documentsDirect=%@",documentsDirect);     NSArray *Librarypaths =  NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSDocumentDirectory, YES);    NSString* libraryDirectory  = [Librarypaths objectAtIndex:0];    NSLog(@">>Librarypaths.length =%d",[Librarypaths count]);     assert(1 < Librarypaths.count);         NSLog(@"libraryDirectory=%@",libraryDirectory);        //如果要指定其他文件目录,比如Caches目录,需要更换目录工厂常量,上面代码其他的可不变    NSArray *pathcaches=NSSearchPathForDirectoriesInDomains(NSCachesDirectory                                                       , NSUserDomainMask                                                       , YES);    NSString* cacheDirectory  = [pathcaches objectAtIndex:0];    NSLog(@"cacheDirectory=%@",cacheDirectory);    /**     使用NSSearchPathForDirectoriesInDomains只能定位Caches目录和Documents目录。          tmp目录,不能按照上面的做法获得目录了,有个函数可以获得应用的根目录     */    NSString *tempDir1=NSHomeDirectory() ;    NSString *tempDir2=NSTemporaryDirectory();    NSLog(@"tempDir1=%@",tempDir1);    NSLog(@"tempDir2=%@",tempDir2);

  归档 普通自定义对象和字节流之间的转换

 序列化 某些特定类型(NSDictionary, NSArray, NSString, NSDate, NSNumber,NSData)的数据和字节流之间(通常将其保存为plist文件)的转换

 

 2.1 归档

 如果我们需要将自定义的一个对象保存到文件,应该如何做呢? 

这里引入两个东西:一个是NSCoding协议 ;另一个是NSKeyedArchiver,NSKeyedArchiver其实继承于NSCoder,可以以键值对的方式将对象的属性进行序列化和反序列化。 
具体的过程可以这样描述 通过NSKeyedArchiver 可以将实现了NSCoding协议的对象 和 字节流 相互转换 。

像一些框架中的数据类型如NSDictionary,NSArray,NSString... 都已经实现了NSCoding协议,所以可以直接对他们进行归档操作。

  这里来一个比较完整的例子,一个Address类,一个User类,User类下有个Address类型的属性

Java代码 复制代码 收藏代码
  1. #import <Foundation/Foundation.h>  
  2.   
  3. @interface Address : NSObject<NSCoding>  
  4. {  
  5.     NSString *country;  
  6.     NSString *city;  
  7. }  
  8. @property(nonatomic,copy) NSString *country;  
  9. @property(nonatomic,copy) NSString *city;   
  10. @end  
#import <Foundation/Foundation.h>@interface Address : NSObject<NSCoding>{    NSString *country;    NSString *city;}@property(nonatomic,copy) NSString *country;@property(nonatomic,copy) NSString *city; @end

 

Java代码 复制代码 收藏代码
  1. #import "Address.h"  
  2.   
  3. @implementation Address  
  4. @synthesize country;  
  5. @synthesize city;  
  6. - (void)encodeWithCoder:(NSCoder *)aCoder{  
  7.     [aCoder encodeObject:country forKey:@"country"];  
  8.     [aCoder encodeObject:city forKey:@"city"];  
  9. }  
  10. - (id)initWithCoder:(NSCoder *)aDecoder{  
  11.     if (self = [super init]) {  
  12.         [self setCountry:[aDecoder decodeObjectForKey:@"country"]];  
  13.         [self setCity:[aDecoder decodeObjectForKey:@"city"]];  
  14.     } return self;  
  15. }  
  16. @end  
#import "Address.h"@implementation Address@synthesize country;@synthesize city;- (void)encodeWithCoder:(NSCoder *)aCoder{    [aCoder encodeObject:country forKey:@"country"];    [aCoder encodeObject:city forKey:@"city"];}- (id)initWithCoder:(NSCoder *)aDecoder{    if (self = [super init]) {        [self setCountry:[aDecoder decodeObjectForKey:@"country"]];        [self setCity:[aDecoder decodeObjectForKey:@"city"]];    } return self;}@end

 

Java代码 复制代码 收藏代码
  1. #import <Foundation/Foundation.h>  
  2. #import "Address.h"  
  3. @interface User : NSObject<NSCoding>{  
  4.     NSString *_name;  
  5.     NSString *_password;  
  6.     Address *_address;  
  7. }  
  8. @property(nonatomic,copy) NSString *name;  
  9. @property(nonatomic,copy) NSString *password;  
  10. @property(nonatomic,retain) Address *address;  
  11.   
  12. @end  
#import <Foundation/Foundation.h>#import "Address.h"@interface User : NSObject<NSCoding>{    NSString *_name;    NSString *_password;    Address *_address;}@property(nonatomic,copy) NSString *name;@property(nonatomic,copy) NSString *password;@property(nonatomic,retain) Address *address;@end

 

Java代码 复制代码 收藏代码
  1. #import "User.h"  
  2.   
  3.   
  4. @implementation User  
  5. @synthesize name = _name;  
  6. @synthesize password = _password;  
  7. @synthesize address = _address;  
  8.   
  9. - (void)encodeWithCoder:(NSCoder *)aCoder{  
  10.     [aCoder encodeObject:_name forKey:@"name"];  
  11.     [aCoder encodeObject:_password forKey:@"password"];  
  12.     [aCoder encodeObject:_address forKey:@"address"];  
  13. }  
  14. - (id)initWithCoder:(NSCoder *)aDecoder{  
  15.     if (self = [super init]) {  
  16.         [self setName:[aDecoder decodeObjectForKey:@"name"]];  
  17.         [self setPassword:[aDecoder decodeObjectForKey:@"password"]];  
  18.         [self setAddress:[aDecoder decodeObjectForKey:@"address"]];  
  19.     }  
  20.     return self;  
  21. }  
  22.   
  23. @end  
#import "User.h"@implementation User@synthesize name = _name;@synthesize password = _password;@synthesize address = _address;- (void)encodeWithCoder:(NSCoder *)aCoder{    [aCoder encodeObject:_name forKey:@"name"];    [aCoder encodeObject:_password forKey:@"password"];    [aCoder encodeObject:_address forKey:@"address"];}- (id)initWithCoder:(NSCoder *)aDecoder{    if (self = [super init]) {        [self setName:[aDecoder decodeObjectForKey:@"name"]];        [self setPassword:[aDecoder decodeObjectForKey:@"password"]];        [self setAddress:[aDecoder decodeObjectForKey:@"address"]];    }    return self;}@end

 操作应用

Java代码 复制代码 收藏代码
  1. NSString *tempDir2=NSTemporaryDirectory();      
  2.      
  3.      
  4. // Do any additional setup after loading the view, typically from a nib.  
  5.    Address *myAddress = [[Address alloc] init] ;  
  6.    myAddress.country = @"中国";  
  7.    myAddress.city = @"杭州";  
  8.    User *user = [[User alloc] init] ;  
  9.      
  10.    user.name = @"卢克";  
  11.    user.password = @"lukejin";  
  12.    user.address = myAddress;  
  13.    //归档  保存的是plist的二进制数据格式  
  14.    NSString *path = [tempDir2 stringByAppendingPathComponent:@"user"];  
  15.    [NSKeyedArchiver archiveRootObject:user toFile:path];  
  16.      
  17.      
  18.    //从文档中读取  
  19.    User *object = [NSKeyedUnarchiver unarchiveObjectWithFile:path];  
  20.    NSLog(@"object.name : %@",object.name);  
 NSString *tempDir2=NSTemporaryDirectory();            	// Do any additional setup after loading the view, typically from a nib.    Address *myAddress = [[Address alloc] init] ;    myAddress.country = @"中国";    myAddress.city = @"杭州";    User *user = [[User alloc] init] ;        user.name = @"卢克";    user.password = @"lukejin";    user.address = myAddress;    //归档  保存的是plist的二进制数据格式    NSString *path = [tempDir2 stringByAppendingPathComponent:@"user"];    [NSKeyedArchiver archiveRootObject:user toFile:path];            //从文档中读取    User *object = [NSKeyedUnarchiver unarchiveObjectWithFile:path];    NSLog(@"object.name : %@",object.name);

 

使用数据对象自带的方法,如字典类写文件:

数据:

Java代码 复制代码 收藏代码
  1. NSMutableDictionary *dataDictionary = [[NSMutableDictionary alloc] init] ;  
  2.   [dataDictionary setValue:[NSNumber numberWithInt:222] forKey:@"intNumber"];  
  3.   [dataDictionary setValue:[NSArray arrayWithObjects:@"1",@"2", nil] forKey:@"testArray"];  
  NSMutableDictionary *dataDictionary = [[NSMutableDictionary alloc] init] ;    [dataDictionary setValue:[NSNumber numberWithInt:222] forKey:@"intNumber"];    [dataDictionary setValue:[NSArray arrayWithObjects:@"1",@"2", nil] forKey:@"testArray"];

 写文件

Java代码 复制代码 收藏代码
  1. [dataDictionary writeToFile:@"/Users/zhoumoban/Desktop/test.plist" atomically:YES];  
[dataDictionary writeToFile:@"/Users/zhoumoban/Desktop/test.plist" atomically:YES];

 读文件:

Java代码 复制代码 收藏代码
  1. NSDictionary *dictionaryFromFile = [NSDictionary dictionaryWithContentsOfFile:@"/Users/zhoumoban/Desktop/test.plist"];  
  2.    NSLog(@"%@",[dictionaryFromFile objectForKey:@"intNumber"]);  
 NSDictionary *dictionaryFromFile = [NSDictionary dictionaryWithContentsOfFile:@"/Users/zhoumoban/Desktop/test.plist"];    NSLog(@"%@",[dictionaryFromFile objectForKey:@"intNumber"]);

 另外:使用NSPropertyListSerialization类。通过NSPropertyListSerialization类可以将数据对象直接转成NSData或者直接写到文件或者流中去

Java代码 复制代码 收藏代码
  1. NSString *error;  
  2.       
  3.     NSData *xmlData = [NSPropertyListSerialization dataFromPropertyList:dataDictionary format:NSPropertyListXMLFormat_v1_0 errorDescription:&error];  
  4.       
  5.     if(xmlData) {  
  6.         NSLog(@"No error creating XML data.");  
  7.         [xmlData writeToFile:@"/Users/zhoumoban/Desktop/test2.plist" atomically:YES];  
  8.     } else {  
  9.         if (error) {  
  10.             NSLog(@"error:%@", error);  
  11.            // [error release];  
  12.         }  
  13.     }  
  14.      //读取  
  15.     NSDictionary *dictionaryFromFile2 = (NSDictionary *)[NSPropertyListSerialization propertyListWithData:[NSData dataWithContentsOfFile:@"/Users/zhoumoban/Desktop/test2.plist"] options:0 format:NULL error:&error];  
  16.     NSLog(@"===%@",[dictionaryFromFile2 objectForKey:@"intNumber"]);  

iOS 各种系统文件目录 临时,缓存,document,lib,归档,序列化