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

时间：2023-03-09 17:18:23
iOS 各种系统文件目录 临时，缓存，document,lib,归档，序列化
  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. NSString *documentsDirect=[paths1 objectAtIndex:0];
  10. assert(1 == paths1.count);
  11. NSLog(@">>documentsDirect=%@",documentsDirect);
  12. NSArray *Librarypaths =  NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSDocumentDirectory, YES);
  13. NSString* libraryDirectory  = [Librarypaths objectAtIndex:0];
  14. NSLog(@">>Librarypaths.length =%d",[Librarypaths count]);
  15. assert(1 < Librarypaths.count);
  16. NSLog(@"libraryDirectory=%@",libraryDirectory);
  17. //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
  18. NSArray *pathcaches=NSSearchPathForDirectoriesInDomains(NSCachesDirectory
  19. , NSUserDomainMask
  20. , YES);
  21. NSString* cacheDirectory  = [pathcaches objectAtIndex:0];
  22. NSLog(@"cacheDirectory=%@",cacheDirectory);
  23. /**
  24. 使用NSSearchPathForDirectoriesInDomains只能定位Caches目录和Documents目录。
  25. 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
  26. */
  27. NSString *tempDir1=NSHomeDirectory() ;
  28. NSString *tempDir2=NSTemporaryDirectory();
  29. NSLog(@"tempDir1=%@",tempDir1);
  30. 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

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

@interface Address : NSObject<NSCoding>

{

    NSString *country;

    NSString *city;

}

@property(nonatomic,copy) NSString *country;

@property(nonatomic,copy) NSString *city;

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

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

  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

  1. [dataDictionary writeToFile:@"/Users/zhoumoban/Desktop/test.plist" atomically:YES];
[dataDictionary writeToFile:@"/Users/zhoumoban/Desktop/test.plist" atomically:YES];

读文件：

  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

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