看过一篇封装CoreData的文章挺不错，有基本使用封装，但是没有写怎么与tableView结合使用，我自己用的过程有些小波折，自己做了一个demo，大家可以看源码一些基本使用应该不难了，
原文：http://blog.csdn.net/pengyuan_d/article/details/40657225?utm_source=tuicool&utm_medium=referral
（1）创建一个Data Model文件，命名为MyModel.xcdatamodeld
（2）创建Users表，添加如图的字段
（3）创建NSManagedObject subclass表实体文件
（4）在Users.m文件中，覆写description方法
CoreDataDBHelper.h #import <Foundation/Foundation.h>
#import <CoreData/CoreData.h> // 本地文件存储的路径
#define PATH [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/sqlite.db"] #define MODEL_NAME @"MyModel" @interface CoreDataDBHelper : NSObject
{
// 1.数据模型对象
NSManagedObjectModel *_managedObjectModel; // 2.创建本地持久文件对象
NSPersistentStoreCoordinator *_persistentStoreCoordinator; // 3.管理数据对象
NSManagedObjectContext *_managedObjectContext;
} // 设计成单例模式
+ (CoreDataDBHelper *)shareCoreDataDBHelper; // 添加数据的方法
- (BOOL)insertDataWithModelName:(NSString *)modelName
setAttributWithDic:(NSDictionary *)params; // 查看
/*
modelName :实体对象类的名字
predicateString :谓词条件
identifers :排序字段集合
ascending :是否升序
*/
- (NSArray *)selectDataWithModelName:(NSString *)modelName
predicateString:(NSString *)predicateString
sort:(NSArray *)identifers
ascending:(BOOL)ascending; // 修改
- (BOOL)updateDataWithModelName:(NSString *)modelName
predicateString:(NSString *)predicateString
setAttributWithDic:(NSDictionary *)params; // 删除
- (BOOL)deleteDataWithModelName:(NSString *)modelName
predicateString:(NSString *)predicateString; @end
CoreDataDBHelper.m
#import "CoreDataDBHelper.h" @implementation CoreDataDBHelper - (instancetype)init
{
self = [super init];
if (self)
{
// 1.数据模型对象
NSURL *modelUrl = [[NSBundle mainBundle] URLForResource:MODEL_NAME withExtension:@"momd"];
_managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelUrl]; // 2.创建本地持久文件对象
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:_managedObjectModel];
// 设置本地数据的保存位置
NSURL *fileUrl = [NSURL fileURLWithPath:PATH]; [_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:fileUrl options:nil error:nil]; // 3.管理数据对象
_managedObjectContext = [[NSManagedObjectContext alloc] init];
[_managedObjectContext setPersistentStoreCoordinator:_persistentStoreCoordinator];
}
return self;
} // 设计成单例模式
+ (CoreDataDBHelper *)shareCoreDataDBHelper
{
static CoreDataDBHelper *coreDataDBHelper = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
coreDataDBHelper = [[CoreDataDBHelper alloc] init];
}); return coreDataDBHelper;
} // 添加数据的方法
/*
params : @{
@"name":@"张三"，
@"age":@20
}
*/
- (BOOL)insertDataWithModelName:(NSString *)modelName
setAttributWithDic:(NSDictionary *)params
{
NSEntityDescription *entity = [NSEntityDescription insertNewObjectForEntityForName:modelName inManagedObjectContext:_managedObjectContext]; // 遍历参数字典
for (NSString *key in params)
{
SEL selector = [self selWithKeyName:key];
if ([entity respondsToSelector:selector])
{
[entity performSelector:selector withObject:params[key]];
}
}
[_managedObjectContext insertObject:entity]; // 保存到本地
return [_managedObjectContext save:nil];
} // 查看
/*
modelName :实体对象类的名字
predicateString :谓词条件
identifers :排序字段集合
ascending :是否升序
*/
- (NSArray *)selectDataWithModelName:(NSString *)modelName
predicateString:(NSString *)predicateString
sort:(NSArray *)identifers
ascending:(BOOL)ascending
{
// 1.创建实体对象
NSEntityDescription *entity = [NSEntityDescription entityForName:modelName inManagedObjectContext:_managedObjectContext]; // 2.创建一个查询对象
NSFetchRequest *request = [[NSFetchRequest alloc] init];
// 告诉查询对象你要查询的数据类型
[request setEntity:entity]; // 添加查询条件
if (predicateString != nil || [predicateString isEqualToString:@""])
{
NSPredicate *predicate = [NSPredicate predicateWithFormat:predicateString];
[request setPredicate:predicate];
} // 3.设置排序
NSMutableArray *sortDescriptors = [NSMutableArray array];
for (NSString *identifer in identifers)
{
// 创建排序对象
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:identifer ascending:ascending];
// 把排序对象添加到数组中
[sortDescriptors addObject:sortDescriptor];
}
// 把排序对象设置到查询对象里面
[request setSortDescriptors:sortDescriptors]; // 3.开始查询
return [_managedObjectContext executeFetchRequest:request error:nil];
} // 修改
- (BOOL)updateDataWithModelName:(NSString *)modelName
predicateString:(NSString *)predicateString
setAttributWithDic:(NSDictionary *)params
{
// 获取所有需要修改实体对象
NSArray *entitys = [self selectDataWithModelName:modelName predicateString:predicateString sort:nil ascending:NO]; // 遍历所有的实体对象
for (NSEntityDescription *entity in entitys)
{
// 修改对象的属性
for (NSString *key in params)
{
SEL selector = [self selWithKeyName:key];
if ([entity respondsToSelector:selector])
{
[entity performSelector:selector withObject:params[key]];
}
}
} return [_managedObjectContext save:nil]; } // 删除
- (BOOL)deleteDataWithModelName:(NSString *)modelName
predicateString:(NSString *)predicateString
{
// 获取所有需要修改实体对象
NSArray *entitys = [self selectDataWithModelName:modelName predicateString:predicateString sort:nil ascending:NO]; // 遍历所有的实体对象
for (NSEntityDescription *entity in entitys)
{
// 删除对象
[_managedObjectContext deleteObject:entity]; } return [_managedObjectContext save:nil];
} // 通过一个字符串反回一个set方法
- (SEL)selWithKeyName:(NSString *)keyName
{
NSString *first = [[keyName substringToIndex:1] uppercaseString];
NSString *end = [keyName substringFromIndex:1];
NSString *selString = [NSString stringWithFormat:@"set%@%@:",first,end];
return NSSelectorFromString(selString);
} @end