IOS基础：UserDefault存储小量数据

自定义对象：

.h文件

Objective-c代码


#import <Foundation/Foundation.h>

@interface MyObject : NSObject

{

NSNumber* lowValue;

NSNumber* highValue;

NSString* titleString;

}

@property(nonatomic, retain)NSNumber* lowValue;

@property(nonatomic, retain)NSNumber* highValue;

@property(nonatomic, retain)NSString* titleString;

@end

.m文件：

Objective-c代码


#import "MyObject.h"

@implementation MyObject

@synthesize lowValue, highValue, titleString;

- (void)encodeWithCoder:(NSCoder *)encoder

{

[encoder encodeObject:self.lowValue forKey:@"lowValue"];

[encoder encodeObject:self.highValue forKey:@"highValue"];

[encoder encodeObject:self.titleString forKey:@"titleString"];

}

- (id)initWithCoder:(NSCoder *)decoder

{

if(self = [super init])

{

self.lowValue = [decoder decodeObjectForKey:@"lowValue"];

self.highValue = [decoder decodeObjectForKey:@"highValue"];

self.titleString = [decoder decodeObjectForKey:@"titleString"];

}

return self;

}

@end

保存单个MyObject方法:

Objc代码


- (void)saveCustomObject:(MyObject *)obj

{

NSData *myEncodedObject = [NSKeyedArchiver archivedDataWithRootObject:obj];

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

[defaults setObject:myEncodedObject forKey:@"myEncodedObjectKey"];

}

- (MyObject *)loadCustomObjectWithKey:(NSString *)key

{

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

NSData *myEncodedObject = [defaults objectForKey:key];

MyObject *obj = (MyObject *)[NSKeyedUnarchiver unarchiveObjectWithData: myEncodedObject];

return obj;

}

保存：

MyObject* testObj = [[MyObject alloc] init];

testObj.lowValue =[NSNumber numberWithFloat:122.2 ];

testObj.highValue = [NSNumber numberWithFloat:19888 ];

testObj.titleString = @“baoyu”;

读取：

MyObject* obj = [self loadCustomObjectWithKey:@"myEncodedObjectKey"];

NSLog(@"%f, %f, %@", [obj.lowValue floatValue], [obj.highValue floatValue], obj.titleString);

保存多个MyObject方法：

Objc代码


保存：

NSMutableArray* array = [[NSMutableArray alloc] init];

for(int i=0; i<3; i++)

{

MyObject* testObj = [[MyObject alloc] init];

testObj.lowValue =[NSNumber numberWithFloat:122.2+i ];

testObj.highValue = [NSNumber numberWithFloat:19888+i ];

testObj.titleString = [NSString stringWithFormat:@"BAOYU%d", i];

[array addObject:testObj];

}

[[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:array] forKey:@"myarray"];

读取：

NSData* data = [[NSUserDefaults standardUserDefaults] objectForKey:@"myarray"];

NSArray *oldSavedArray = [NSKeyedUnarchiver unarchiveObjectWithData:data];

for(MyObject* obj in oldSavedArray)

{

NSLog(@"%f, %f, %@", [obj.lowValue floatValue], [obj.highValue floatValue], obj.titleString);

}