自己写简单CoreDataManager封装对CoreData操作

关于CoreData的介绍太多，网上一搜大把全是，这里不介绍CoreData，直接上代码，注释写的很详细，应该很容易理解，暂时现做简单的增删该查，后面有时间再做修改完善。

CoreDataManager.h

 //
 //  CoreDataManager.h
 //  UCaiYuan
 //
 //  Created by wanyakun on 16/1/6.
 //  Copyright © 2016年 com.ucaiyuan. All rights reserved.
 //

 #import <Foundation/Foundation.h>

 @interface CoreDataManager : NSObject

 +(CoreDataManager *)defaultManager;

 /**
  *  插入单条数据到Entity
  *
  *  @param entity 实体字典
  *  @param name   Entity名称
  */
 - (BOOL)insertCoreDataWithEntity:(NSDictionary *)entity name:(NSString *)name;

 /**
  *  根据查询条件从实体中查询数据
  *
  *  @param entityName Entity名称
  *  @param predicate  查询条件
  *
  *  @return 字典数组
  */
 - (NSMutableArray *)selectCoreDataFromName:(NSString *)name predicate:(NSString *)predicate;

 /**
  *  更新单条数据到Entity
  *
  *  @param entity    更新内容
  *  @param name      Entity名字
  *  @param predicate 更新条件
  *
  *  @return 是否更新成功
  */
 - (BOOL)updateCoreDataWithEntity:(NSDictionary *)entity name:(NSString *)name predicate:(NSString *)predicate;

 /**
  *  从Entity中删除数据
  *
  *  @param entity    更新内容
  *  @param name      Entity名字
  *  @param predicate 更新条件
  *
  *  @return 是否删除成功
  */
 - (BOOL)deleteCoreDataWithName:(NSString *)name predicate:(NSString *)predicate;

 @end

CoreDataManager.m

 //
 //  CoreDataManager.m
 //  UCaiYuan
 //
 //  Created by wanyakun on 16/1/6.
 //  Copyright © 2016年 com.ucaiyuan. All rights reserved.
 //

 #import "CoreDataManager.h"

 @interface CoreDataManager ()
 /**
  *  负责应用和数据直接的交互CRUD
  */
 @property (strong, nonatomic) NSManagedObjectContext *managedObjectContext;
 /**
  *  添加持久化存储库（比如SQLite数据库）
  */
 @property (strong, nonatomic) NSPersistentStoreCoordinator *persistentStoreCoordinator;
 /**
  *  代表CoreData模型文件
  */
 @property (strong, nonatomic) NSManagedObjectModel *managedObjectModel;
 @end

 @implementation CoreDataManager

 #pragma mark - 单例
 +(CoreDataManager *)defaultManager {
     static dispatch_once_t predicate;
     static CoreDataManager * defaultManager;
     dispatch_once(&predicate, ^{
         defaultManager=[[CoreDataManager alloc] init];
     });
     return defaultManager;
 }

 #pragma mark - public method
 /**
  *  插入单条数据到Entity
  *
  *  @param entity 实体字典
  *  @param name   Entity名称
  */
 - (BOOL)insertCoreDataWithEntity:(NSDictionary *)entity name:(NSString *)name
 {
     NSManagedObject *object = [NSEntityDescription insertNewObjectForEntityForName:name inManagedObjectContext:self.managedObjectContext];
     [object setValuesForKeysWithDictionary:entity];
     // 利用上下文对象，将数据同步到持久化存储库
     NSError *error = nil;
     BOOL success = [self.managedObjectContext save:&error];
     if (!success) {
         NSLog(@"保存数据到数据库错误：%@",[error localizedDescription]);
         return NO;
     }
     return YES;
 }

 /**
  *  根据查询条件从实体中查询数据
  *
  *  @param entityName Entity名称
  *  @param predicate  查询条件
  *
  *  @return 字典数组
  */
 - (NSMutableArray *)selectCoreDataFromName:(NSString *)name predicate:(NSString *)predicate
 {
     NSFetchRequest *request = [[NSFetchRequest alloc] init];

     NSEntityDescription *entity = [NSEntityDescription entityForName:name inManagedObjectContext:self.managedObjectContext];
     request.entity = entity;

     if (predicate) {
         NSPredicate *predicateObject = [NSPredicate predicateWithFormat:predicate];
         request.predicate = predicateObject;
     }

     NSError *error;
     NSArray *fetchedObjects = [self.managedObjectContext executeFetchRequest:request error:&error];
     NSMutableArray *resultArray = [NSMutableArray array];

     for (NSManagedObject *object in fetchedObjects) {
         NSMutableDictionary *dict = [NSMutableDictionary dictionary];
         for (NSPropertyDescription *property in entity.properties) {
             NSString *key = property.name;
             id value = [object valueForKey:key];
             [dict setValue:value forKey:key];
         }
         [resultArray addObject:dict];
     }
     return resultArray;
 }

 /**
  *  更新单条数据到Entity
  *
  *  @param entity    更新内容
  *  @param name      Entity名字
  *  @param predicate 更新条件
  *
  *  @return 是否更新成功
  */
 - (BOOL)updateCoreDataWithEntity:(NSDictionary *)entity name:(NSString *)name predicate:(NSString *)predicate
 {
     NSFetchRequest *request = [[NSFetchRequest alloc] init];

     NSEntityDescription *entityDescription = [NSEntityDescription entityForName:name inManagedObjectContext:self.managedObjectContext];
     request.entity = entityDescription;

     if (predicate) {
         NSPredicate *predicateObject = [NSPredicate predicateWithFormat:predicate];
         request.predicate = predicateObject;
     }

     NSError *error;
     NSArray *fetchedObjects = [self.managedObjectContext executeFetchRequest:request error:&error];

     for (NSManagedObject *object in fetchedObjects) {
         [object setValuesForKeysWithDictionary:entity];
     }

     BOOL success = [self.managedObjectContext save:&error];
     if (!success) {
         NSLog(@"更新数据到数据库错误：%@",[error localizedDescription]);
         return NO;
     }
     return YES;
 }

 /**
  *  从Entity中删除数据
  *
  *  @param entity    更新内容
  *  @param name      Entity名字
  *  @param predicate 更新条件
  *
  *  @return 是否删除成功
  */
 - (BOOL)deleteCoreDataWithName:(NSString *)name predicate:(NSString *)predicate
 {
     NSFetchRequest *request = [[NSFetchRequest alloc] init];

     NSEntityDescription *entityDescription = [NSEntityDescription entityForName:name inManagedObjectContext:self.managedObjectContext];
     request.entity = entityDescription;

     if (predicate) {
         NSPredicate *predicateObject = [NSPredicate predicateWithFormat:predicate];
         request.predicate = predicateObject;
     }

     NSError *error;
     NSArray *fetchedObjects = [self.managedObjectContext executeFetchRequest:request error:&error];

     for (NSManagedObject *object in fetchedObjects) {
         [self.managedObjectContext deleteObject:object];
     }

     BOOL success = [self.managedObjectContext save:&error];
     if (!success) {
         NSLog(@"删除数据出错：error:%@",error);
         return NO;
     }
     return YES;
 }

 #pragma mark - private method
 //获取Documents路径
 - (NSURL *)applicationDocumentsDirectory
 {
     return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
 }

 - (NSString *)bundleName
 {
     return [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleName"];
 }

 #pragma mark - getter setter
 - (NSManagedObjectContext *)managedObjectContext
 {
     if (_managedObjectContext == nil) {
         _managedObjectContext = [[NSManagedObjectContext alloc] init];
         _managedObjectContext.persistentStoreCoordinator = [self persistentStoreCoordinator];
     }
     return _managedObjectContext;
 }

 - (NSPersistentStoreCoordinator *)persistentStoreCoordinator
 {
     if (_persistentStoreCoordinator == nil) {
         _persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:self.managedObjectModel];

         NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:[self bundleName]];
         NSError *error = nil;
         if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) {
             NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
             abort();
         }
     }
     return _persistentStoreCoordinator;
 }

 - (NSManagedObjectModel *)managedObjectModel
 {
     if (_managedObjectModel == nil) {
         _managedObjectModel = [NSManagedObjectModel mergedModelFromBundles:nil];
     }
     return _managedObjectModel;
 }

 @end