IOS基础：UserDefault存储小量数据

自定义对象：

.h文件

 #import

 @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：

 #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);
     }