使用NSUserDefaults保存自定义对象

转自http://zani.iteye.com/blog/1431239

.h文件

#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

#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:

- (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：

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);
    }